EP1744835B1 - Method for applying a film to a planar substrate, deflecting element and device for applying a film to a planar substrate - Google Patents

Method for applying a film to a planar substrate, deflecting element and device for applying a film to a planar substrate Download PDF

Info

Publication number
EP1744835B1
EP1744835B1 EP05729869A EP05729869A EP1744835B1 EP 1744835 B1 EP1744835 B1 EP 1744835B1 EP 05729869 A EP05729869 A EP 05729869A EP 05729869 A EP05729869 A EP 05729869A EP 1744835 B1 EP1744835 B1 EP 1744835B1
Authority
EP
European Patent Office
Prior art keywords
substrate
deflection
film
edge
planar substrate
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
EP05729869A
Other languages
German (de)
French (fr)
Other versions
EP1744835A2 (en
Inventor
Juergen Steckelberg
Gerd Brockmann
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nordson Corp
Original Assignee
Nordson Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nordson Corp filed Critical Nordson Corp
Publication of EP1744835A2 publication Critical patent/EP1744835A2/en
Application granted granted Critical
Publication of EP1744835B1 publication Critical patent/EP1744835B1/en
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05C—APPARATUS FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05C5/00—Apparatus in which liquid or other fluent material is projected, poured or allowed to flow on to the surface of the work
    • B05C5/007—Slide-hopper coaters, i.e. apparatus in which the liquid or other fluent material flows freely on an inclined surface before contacting the work
    • B05C5/008—Slide-hopper curtain coaters
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05C—APPARATUS FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05C5/00—Apparatus in which liquid or other fluent material is projected, poured or allowed to flow on to the surface of the work
    • B05C5/02—Apparatus in which liquid or other fluent material is projected, poured or allowed to flow on to the surface of the work the liquid or other fluent material being discharged through an outlet orifice by pressure, e.g. from an outlet device in contact or almost in contact, with the work
    • B05C5/0245—Apparatus in which liquid or other fluent material is projected, poured or allowed to flow on to the surface of the work the liquid or other fluent material being discharged through an outlet orifice by pressure, e.g. from an outlet device in contact or almost in contact, with the work for applying liquid or other fluent material to a moving work of indefinite length, e.g. to a moving web
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D1/00—Processes for applying liquids or other fluent materials
    • B05D1/26—Processes for applying liquids or other fluent materials performed by applying the liquid or other fluent material from an outlet device in contact with, or almost in contact with, the surface
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D7/00—Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials
    • B05D7/02—Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials to macromolecular substances, e.g. rubber
    • B05D7/04—Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials to macromolecular substances, e.g. rubber to surfaces of films or sheets
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B37/00—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding
    • B32B37/0007—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding involving treatment or provisions in order to avoid deformation or air inclusion, e.g. to improve surface quality
    • B32B37/003—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding involving treatment or provisions in order to avoid deformation or air inclusion, e.g. to improve surface quality to avoid air inclusion
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B38/00—Ancillary operations in connection with laminating processes
    • B32B38/18—Handling of layers or the laminate
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D1/00—Processes for applying liquids or other fluent materials
    • B05D1/007—Processes for applying liquids or other fluent materials using an electrostatic field
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D1/00—Processes for applying liquids or other fluent materials
    • B05D1/26—Processes for applying liquids or other fluent materials performed by applying the liquid or other fluent material from an outlet device in contact with, or almost in contact with, the surface
    • B05D1/265—Extrusion coatings
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D2252/00—Sheets
    • B05D2252/02—Sheets of indefinite length
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2309/00—Parameters for the laminating or treatment process; Apparatus details
    • B32B2309/06—Angles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2309/00—Parameters for the laminating or treatment process; Apparatus details
    • B32B2309/14—Velocity, e.g. feed speeds
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2310/00—Treatment by energy or chemical effects
    • B32B2310/021—Treatment by energy or chemical effects using electrical effects

Definitions

  • the invention relates to a method for applying a film to a planar, in particular airtight substrate.
  • the invention further relates to a deflection element for deflecting a planar, in particular airtight substrate with at least one guide surface formed for guiding a planar substrate and a further, with the guide surface an edge for deflecting a planar substrate enclosing guide surface.
  • the invention relates to a device for applying a film to a flat, in particular air-impermeable substrate with a feed element for feeding the planar substrate and an applicator device for applying a film.
  • the invention relates to the use of a deflecting element.
  • US 2002/0090463 A1 describes a coating process in which a web is stabilized by means of an air bearing in the area between two pulleys. Vibrations of the web should be minimized by air flowing out of a bearing surface.
  • a deflecting element of the above-mentioned type is preferably used according to the invention, in which at least one compressed air channel extends to the edge through the deflection element, which terminates in at least one outlet opening in the region of the edge, which is designed so that from this outflowing compressed air to forms the edge running air cushion.
  • the object is achieved by a deflecting element according to claim 11 for deflecting a particular airtight substrate with at least one guide surface for guiding a flat substrate and another, with the guide surface an edge for deflecting a planar substrate enclosing guide surface, in which the two guide surfaces are arranged at an angle to each other, that the substrate is sharply deflected during its movement along the two guide surfaces.
  • the planar substrate in the deflection at the edge influenced by an air cushion.
  • a force acts on the substrate.
  • This force acts perpendicular to the component on which the deflection takes place, so that it comes to friction.
  • it is important to keep the friction as low as possible.
  • the friction can be significantly reduced, which protects the planar substrate both in terms of mechanical and thermal influences.
  • the air cushion is formed from cold air
  • the planar substrate is additionally cooled in the deflection region. This is particularly advantageous if a hot-melt adhesive film is applied as the film. In the deflection region, the flat substrate then comes in intimate contact with the hot-melt adhesive film, which causes it to be thermally stressed. This thermal load is reduced by an air cushion of cooled air.
  • the substrate is so influenced by the air cushion that it does not come into direct contact with the edge.
  • there is no solid friction between the sheet substrate and the deflecting component but only fluid friction between the sheet substrate and air cushion, and the deflecting component and the air cushion.
  • Such a fluid friction is significantly less pronounced than a solid friction between flat substrate and the deflecting component, so that thermal and mechanical loads are reduced.
  • the influencing of the planar substrate in the deflection region by means of an air cushion is effected in particular by forming an air cushion between the edge and optionally an area around the edge on the one hand and the substrate on the other hand by air emerging from outlet openings in the region of the edge.
  • the air forming the air cushion should be under at least such a pressure that the contact force exerted on the edge and the edge region by the feed and deflection of the substrate is overcome and a complete separation of the substrate from the edge and the edge region is achieved.
  • a device of the type mentioned above which comprises such a deflection element.
  • the object is achieved by the use of a deflection element of the aforementioned type for deflecting a substrate web in a device for applying a film to the substrate web.
  • a film is understood to mean a coherent, but not necessarily homogeneous, material layer which is dispensed by the application device. Examples of these are thin hot-melt adhesive layers, films or adhesive tapes. When delivered from the applicator, the film is also viewed when the applicator dispenses one or more substances that form a film on the way to the substrate.
  • the film is preferably applied to the planar substrate in such a way that the film is released from the application device in the immediate vicinity of the substrate before the sharp deflection of the planar substrate and initially runs closely adjacent to the substrate.
  • the deposited film and the substrate are then brought into direct contact in the deflection region, so that adhesion takes place between the film and the substrate.
  • the film is as a layer on the substrate and is connected to this. In this way, a pull-off action is exerted on the film delivered by the application device by the supplied flat substrate and the delivery speed of the flat substrate and the delivery speed of the film from the application device, the film thickness is variable.
  • Sharp deflection should be understood in this context to be a change in the direction of the substrate which, with respect to the deflection angle, the deflection radius and the feed rate, is such Redirection achieves that in relation to the substrate thickness takes place in a small space deflection.
  • the deflection angle which should be as pointed.
  • the deflection angle ideally approaches 180 °, ie, the direction of movement of the substrate changes by 180 °, but such an acute angle will be virtually unworkable because technically common substrates such a strong deflection at conventional deflection radii not unscathed survive and tearing or at least partial damage to the substrate is to be feared.
  • the deflection radius which should be chosen as small as possible. Again, the reduction of the deflection radius is limited by the risk of damaging the substrate. Deflection radius and deflection angle are related to some extent, ie when choosing a small deflection angle, a smaller deflection radius can be selected than when a larger deflection angle is selected. Conversely, with a small deflection radius, a larger deflection angle must be selected than with a larger deflection radius.
  • the feed rate of the substrate is related to the deflection radius to be selected and the deflection angle to be selected, in order to achieve a sharp deflection. The higher the speed of the flat substrate in the deflection region, the larger the deflection angle and the smaller the deflection radius must be selected in order to achieve the effect achieved by the invention.
  • the deflecting region is understood to mean the smallest region in the substrate running path which is located behind the coating apparatus and in whose immediately adjoining environment the substrate moves in a translatory movement. It is thus the area in which the deflection takes place and in which the radius of curvature of the substrate pathway differs greatly from the radii of curvature in the adjacent areas.
  • the substrate trace is the path that a portion of the substrate travels during the process.
  • the invention offers the advantage that the probability of air inclusions when applying a film to a flat substrate is significantly reduced. As a result of the sharp deflection, air that may still be present between the substrate and the film is pushed out of and / or out of this intermediate region, so that this air can not form any air pockets.
  • the reduction of the air inclusions is achieved even at high to very high feed rates and thus achievable high processing speeds.
  • the reduction of air inclusions is achieved even if both the substrate and the film are impermeable to air; in such a. In the event, even the smallest amounts of air could not escape after the application of the film.
  • a high processing speed is understood to mean above 150 m / min; under a very high processing speed such over 500 m / min.
  • Another advantage of the invention is the high process reliability. In plants that are operated continuously, interruptions in production lead to considerable costs. The high process reliability also contributes to lower costs.
  • the sharp deflection of the planar substrate is achieved in that the radius of curvature of the planar substrate on the side facing the film in the deflection region is smaller than 8 mm.
  • the radius of curvature is calculated by a compensation circle, which is inscribed in the contour of the substrate in the deflection region. Due to the small radius of curvature, a large angle between the substrate and the film brought into contact with the substrate arises in the deflection region in comparison to previous methods. Due to this large angle, the air in this area is forced out of the area where the film is in immediate, ie physical contact with the substrate device. This greatly reduces the chance of air pockets.
  • the radius of curvature is less than 6 mm, in particular less than 4 mm.
  • the smaller the radius of curvature the more effectively the air is displaced from the area between the substrate and the film, and the lower the probability of air inclusions. From this point of view, therefore, the smallest possible radii of curvature are desirable.
  • the smaller the radius of curvature the greater the load on the substrate. In particular, the risk of cracks or wrinkles increases. For each substrate and each film, it must be determined in the course of a series of experiments how small the radius of curvature can be chosen at a given processing speed, so that damage to the substrate does not occur.
  • the deflection of the planar substrate by moving, in particular pulling the surface substrate over an edge is effected.
  • An edge allows the expression of a small radius of curvature with structurally simple means. At the same time a rigid structure is achieved, which reduces vibrations.
  • the deflection of the planar substrate is effected by moving, in particular pulling the surface substrate over an edge whose radius of curvature is smaller than 3 mm, in particular 2 mm, reduced by the thickness of the substrate
  • the flat substrate is a transparent film.
  • air pockets are particularly quick to catch the eye. For this reason, the use of the air-entrapping method according to the invention is particularly favorable.
  • the film is brought into close proximity to the sheet substrate at a location having a distance of 0-20 mm, in particular 1-10 mm from the deflection.
  • the film is applied to the planar substrate and the subsequent deflection of the substrate results in the formation of an adhesive force between the two partners, due to which they ultimately adhere to one another.
  • air which is located in the area between film and substrate, from this area u.a. displaced by dynamically generated local barometric pressure changes. If the distance between the location where the film comes into close proximity to the surface substrate and the deflection area is too small, the air will not have enough time to leave this area. If the distance is too large, there is a risk that film and substrate adhere to each other before deflecting, so that the following sharp deflecting the air is prevented from escaping and can form air pockets.
  • the smaller the included angle the higher the likelihood that air pockets will be avoided. However, as the angle decreases, so does the load on the substrate. It is thus to determine in advance for each substrate, each film and each processing speed, how small this included angle can be chosen without damaging the substrate.
  • planar substrate is supplied as a substrate web.
  • the method of applying the film may be performed as a continuous process. Since any start-up problems of the process are largely avoided, in particular only once Start the process occur, in this way a particularly efficient and therefore cost-effective production possible.
  • the substrate is first guided on a, preferably cooled, guide roller, then fed back from the guide roller along a guide roller with smaller diameter compared to the guide roller of the guide roller on the applicator to and after deflecting the guide roller.
  • the speed at which the film is applied to the sheet substrate is determined by the rotational speed of the guide roll.
  • the voltage of the substrate, and thus the voltage applied to the substrate in the deflection, by adjusting the distance between the deflection process and the guide roller is very sensitive adjustable. In the case of heat-sensitive substrates, the fact that the guide roller and / or the deflecting element are cooled reduces or prevents thermal damage.
  • the planar substrate in the deflection region is exposed to an electrostatic field which has a field strength of more than 5 kV / m at at least one point in the deflection region.
  • an electrostatic field additionally reduces the inclination to air inclusions. Due to the curvature of the deflecting element in the region of the edge, an advantageous reinforcement of the field strength in the deflection region is achieved since the field lines are concentrated. Such a field enhancement can also be achieved by reducing the distance between the electrode and deflecting element.
  • a deflecting element is preferred that has an edge with a radius of curvature of less than 5 mm, in particular less than 3 mm, in particular less than 2 mm. If a planar substrate is pulled over such an edge, then, when the planar substrate always has contact with the deflecting element, a correspondingly small radius of curvature arises on the side facing the film in the deflecting region, the advantages of which are described above.
  • the further surface which encloses an edge with the guide surface is preferably also a guide surface designed to guide the surface substrate.
  • the included angle formed by the guide surfaces in the vicinity of the edge is smaller than 120 °, in particular between 45 ° and 90 °, in particular between 55 ° and 75 °. If one or both guide surfaces are curved, then the angle formed in the vicinity of the edge is determined by writing a straight line of equal length of the diameter of the deflection region into the guide surfaces and determining the angle between both equalization lines.
  • the included angle formed by the guide surfaces in the vicinity of the edge represents a compromise between an included angle as low as possible below 180 ° for avoiding stresses for the planar substrate and an included angle as low as possible above 0 ° for reducing air inclusions.
  • angles within the angular intervals indicated above result in a reduction in the tendency of air entrapment.
  • At least one guide surface has a crown, in particular a crown, whose radius of curvature is between 300 mm and 2000 mm.
  • a convex surface can be described in a first approximation by a paraboloid. Such a paraboloid has two major axes and correspondingly two radii of curvature. If these two radii of curvature chosen between 300-2000 mm, so nestled the substrate to the deflection. Thereby, a uniform supply of the substrate is achieved without causing wrinkles in the substrate.
  • a rotatably mounted rod can be used, which is preferably at least supported by the air cushion. Any reduction in the diameter of the rod is limited by the required mechanical strength of the rod limiting.
  • the bearing of the rod can advantageously be achieved by means of an air cushion. This air cushion is generated, for example, within a cavity partially surrounding the rod, which receives the rod secured against falling out, by means of an air channel formed in the deflection element, which extends into the cavity.
  • the guide surfaces are designed as air cushion surfaces.
  • An air cushion surface is understood to mean a surface which can be connected to a compressed air supply such that when a substrate lies on the air cushion surface, an air cushion forms between the two.
  • the friction between the planar substrate and deflecting element is reduced, so that the thermal stress on the planar substrate is reduced.
  • the sheet substrate can be cooled, which reduces its thermal load.
  • the edge is formed by a permeable surface for compressed air, in particular a sieve or fabric element.
  • a permeable surface for compressed air in particular a sieve or fabric element.
  • extending channels are provided for receiving cooling media in the interior of the deflecting element.
  • Suitable cooling media are, for example, water, oil, air and working gases used in refrigeration systems.
  • thermal stress can be placed on the sheet substrate.
  • the cooling medium present in the channels first the deflecting element and thereby the planar substrate are cooled. If an air cushion is located between the planar substrate and the deflecting element, then the cooling medium firstly cools the air which forms the air cushion and thus indirectly the planar substrate.
  • the deflection element has a fish-burr-shaped surface corrugation on the guide surface, in particular on the guide surface.
  • the surface corrugation is arranged so that the planar substrate is stretched outwardly during the movement along the guide surface via the surface corrugation perpendicular to the direction of movement. In this way, the tendency of the substrate to wrinkle is reduced
  • a fine-meshed fabric is provided on the guide surface, in particular the guide surfaces.
  • the fine-meshed fabric serves to distribute outflowing compressed air in such a way that a homogeneous air cushion is formed.
  • a homogeneous air cushion the air pressure, air flow and air temperature differences within the air bag are so small that they do not affect the substrate.
  • a tissue is considered that has more than 10 threads / cm.
  • the application device is arranged such that the point of the substrate travel path at which it is at a minimum distance from the substrate Dispensing opening has, between 0 and 20 mm, in particular between 1 and 10 mm in front of the edge of the deflecting element. Experiments have shown that this can be particularly effectively reduced the formation of air bubbles.
  • a counterelectrode is arranged in the vicinity of the deflection region such that the substrate web path runs between deflecting element and counterelectrode, and the counterelectrode is electrically insulated from other elements, in particular all other elements of the device, and from an electrical potential of magnitude by means of a voltage source at least 1 kV with respect to the other elements of the device is rechargeable.
  • the deflecting element is electrically insulated from other, in particular all other elements of the device and can be charged by means of a voltage source to an electrical potential of at least 1 kV with respect to the other elements of the device.
  • a voltage source to an electrical potential of at least 1 kV with respect to the other elements of the device.
  • an electric field between the deflecting element and the other elements of the machine is constructed. If this electric potential is additionally applied with opposite sign to a potential of a counterelectrode, then the electric field can be amplified.
  • the field lines of the electric field concentrate and form a particularly strong, inhomogeneous electric field there. The electric field has the effect of further reducing the tendency to form air pockets.
  • FIG. 1 shows an application device 10 comprising a substantially wedge-shaped deflection element 12, a cooled deflection roller 14, an application head 16, a counter-electrode 18 and a power supply unit 20.
  • a 20-100 ⁇ m thick substrate web 22 consisting of polypropylene (PP), polyethylene (PE) or polyethylene terephthalate (PET) is deflected in the direction of the application head 16 at a speed of up to 600 m / min.
  • the substrate web 22 runs along a feed guide surface 24 of the deflecting element 12, is deflected sharply at an edge 26 of the deflecting element 12 and then runs along a discharge guide surface 28 in the direction of the arrow P.
  • the guide roller 14 is designed as a cooling roller, wherein the connections for the cooling medium are not shown.
  • the application head 16 is supplied via an adhesive supply line 30 with liquid hot melt adhesive, which has a temperature of 150 ° C. This temperature is depending on the material properties of the substrate and the H thoroughlyklebsztoffs set.
  • the hot-melt adhesive leaves the applicator head 16 through an outlet opening 32 in the form of a thin, transparent adhesive film 34.
  • the applicator head and its outlet opening are arranged relative to the deflecting element such that the adhesive film 34 is approximately parallel to the discharge direction of the substrate and offset by Edge 26 of the deflecting element 12 emerges spaced apart in the feed direction.
  • the adhesive film 34 is preferably in a location in close proximity with the substrate web 22, which is in the direction of the substrate web in front of this edge. At this location, an approximation to a very small distance between substrate web 22 and adhesive film 34 is initially achieved, but still no direct contact.
  • both are sharply deflected by being pulled together over the edge 26.
  • a tensile force is exerted on the substrate web 22 by a device, not shown here, which acts in the direction of the arrow P.
  • the angle ⁇ between the feed guide surface 24 and the discharge guide surface 28 is 60 °.
  • the radius of curvature of the substrate web 22 is 2 mm at the moment it is pulled over the edge 26. Accordingly, the radius of curvature of the substrate web path at the edge 26 is also 2mm. Due to the sharp deflection, the substrate web 22 and the adhesive film 34 come into direct contact and adhere to each other without air entrapment.
  • the deflecting element 12 is grounded. In extension of the feed guide surface 24 and laterally displaced toward the discharge guide surface 28 is opposite the AbrawFroundungs simulation 28, the counter electrode 18. This is charged by a generator 20 relative to the electrical zero level to a constant high voltage of 10-30 kV. As a result, an electric field E forms between the deflection element 12 and the counterelectrode 18, which is particularly large at the edge 26 in particular because of its curvature, since the electric field lines concentrate here.
  • FIG. 2 shows an alternative embodiment of the applicator 10.
  • the substrate web 22 initially runs on a gfs. cooled to dew point guide roller 38 which rotates in the direction of arrow P. From the guide roller 38, the substrate web 22 is deflected by the guide roller 14 and extends along the feed guide surface 24 of the deflecting element 12, around the edge 26 and along the AbrawFhakungs composition 28, from where it in turn reaches the guide roller 38.
  • the deflecting element 12 has a substantially triangular cross-section, but the longest side facing the guide roller 38 is concave and has a radius of curvature which corresponds to the radius of the guide roller 38.
  • the two other side surfaces of the deflecting element 12 are slightly convex.
  • the radius of curvature is greater than that of the guide roller 38 and is for example 1000mm with respect to the major axis, parallel to the axis of rotation the guide roller 38 runs and also 1000mm with respect to the other major axis.
  • An air cushion 40 is located between the substrate web 22 and the deflecting element 12.
  • a cavity 42 is provided in the interior of the deflecting element 12. This is connected via a connection not shown here in connection with a likewise not shown compressed air source, so that the cavity 42 is filled with compressed air.
  • a fine mesh fabric 46 which is part of the deflecting element 12, to the outside and forms between the substrate web 22 and the deflecting element 12th Air cushion 40.
  • a slot 48 extends into the cavity 42. Through the slot 38 occurs in the region of the edge 26 also compressed air and forms an air cushion around the edge 26 from.
  • the substrate web 22 is deflected sharply in the deflection region.
  • the deflection region 36 is the region of the substrate web running path at which the curvature changes greatly.
  • the radius of curvature of the substrate web 22 essentially corresponds to the curvature of the feed guide surface 24.
  • the radius of curvature of the substrate web run path is in the region of Ab technologicalFlickungs Solution 28 substantially equal to the radius of curvature. Between two areas of the deflection region 36, in which the radius of curvature instead of 1000mm is now only 1-6mm.
  • liquid hot adhesive in the form of an adhesive film 34 is discharged onto the substrate web 22.
  • the adhesive film 34 comes in the immediate vicinity of the substrate web 22, but not in direct contact. In the area between the adhesive film 34 and substrate web 22 is air. If adhesive film 34 and substrate web 22 are deflected sharply in the deflection region 36, then the adhesive film is brought into direct contact with the substrate web and this air is pressed out of this region counter to the direction of movement of the substrate web. As a result, the adhesive film 34 then adheres to the substrate web 22 without air inclusions.
  • the hot melt adhesive which forms the adhesive film 34
  • the compressed air in the cavity 42 and the deflecting element is cooled.
  • one or more coolant channels 52 are provided in the deflecting element 12.
  • the coolant channels 52 extend parallel to the axes of rotation of the guide roller 38 and deflecting roller 14.
  • the deflecting element is made of highly conductive material.
  • the deflecting element or heatnäbroughe the deflecting element is made of a sintered metal.
  • sintered metals are suitable for forming lubricious surfaces.
  • an open porosity can be set which, in the application according to the invention, can be advantageously used to form the air cushion.
  • the tension under which the substrate web 22 is on its way along the deflecting element 12 is controlled by the distance of the deflecting element 12 from the center of the guide roller 38, which represents the reference variable.
  • a controlled variable for example, the distance of the substrate 22 from the edge 26 or the frequency of trapped air is used.
  • FIG. 3a shows an alternative embodiment of a deflecting 12.
  • the extending from the cavity 42 to the edge 26 slot 48 terminates in a cavity 54 which is bounded by a very fine mesh screen 56 to the edge 26 out.
  • the web 46 extends from the feed guide surface 24 across the wire 56 along the discharge guide surface 28.
  • the air bag 40 may be varied in thickness in the region of the edge.
  • a perforated plate or similar can be used.
  • FIG. 3b shows the attachment of the fabric 46 by means of clamping blocks 58, which clamp the tissue in a recess 60 and thereby prevent it from being lifted off by the air flowing out of the interior of the deflecting compressed air.
  • the clamping blocks 58 are attached with not visible in this view countersunk screws.
  • Fig. 4 shows an alternative embodiment of the edge 26 of the deflecting 12.
  • a rod 62 is provided which is rotatably supported by ball bearings not shown here.
  • the rod 62 has a diameter of 2 mm and is positioned so that approximately half of its circumference protrudes beyond the extensions of the feed guide surface 24 and the discharge guide surface 28.
  • Fig. 5a schematically shows an embodiment of the surface finish of the feed guide surface 24 and / or the discharge guide surface 28.
  • linearly extending corrugations 64 are formed, so elevations that rise above the base surface of the feed guide surface.
  • These corrugations 64 are provided with a chromium coating for friction reduction and are arranged in the form of a fishbone or V-shaped so that two corrugations converge at a point. All such points lie on a straight line that runs parallel to the sides of the guide surface.
  • the substrate web moves in the direction of the arrow P.
  • the arrangement of the corrugations 64 pulls the substrate web apart when sliding on the guide surface, so that an inclination of the substrate web for wrinkling is reduced.
  • Fig. 5b schematically shows a plan view of the feed guide surface 24, which is covered with the fabric 46.
  • the fabric 46 has a plain weave and a thread density of 10 threads / cm. Below the fabric 46 and thus not visible in the plan view end the tap holes 44 from which compressed air emerges. Through the fabric 46, the compressed air is distributed so that forms a homogeneous air cushion.

Landscapes

  • Engineering & Computer Science (AREA)
  • Quality & Reliability (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Wood Science & Technology (AREA)
  • Application Of Or Painting With Fluid Materials (AREA)
  • Registering, Tensioning, Guiding Webs, And Rollers Therefor (AREA)
  • Shaping Of Tube Ends By Bending Or Straightening (AREA)
  • Lining Or Joining Of Plastics Or The Like (AREA)
  • Absorbent Articles And Supports Therefor (AREA)

Abstract

The invention relates to a method for applying a film to a planar, especially air-impermeable substrate (22), comprising the steps: (a) feeding the planar substrate in a direction of feed towards an application device, (b) applying a film (34) output by the application device (16) to the planar substrate, and (c) sharply deflecting the planar substrate together with the film that is in contact therewith in a deflection area (36) in a discharge direction different from the direction of feed. The invention also relates to a deflecting element (12) for deflecting a planar substrate. Said element comprises at least one guiding surface adapted to guide a planar substrate and an additional guiding surface, forming an edge for sharply deflecting a planar substrate with the first guiding surface. At least one pressure channel extends through the deflecting element towards the edge and runs into at least one outlet opening in the area of the edge, said opening being configured in such a manner that the pressurized air discharged from said opening forms an air cushion (40) which extends around the edge.

Description

Die Erfindung betrifft ein Verfahren zum Auftragen eines Films auf ein flächiges, insbesondere luftundurchlässiges Substrat. Die Erfindung betrifft des Weiteren ein Umlenkelement zum Umlenken eines flächigen, insbesondere luftundurchlässigen Substrats mit mindestens einer zum Führen eines flächigen Substrats ausgebildeten Führungsfläche und einer weiteren, mit der Führungsfläche eine Kante zum Umlenken eines flächigen Substrats einschließende Führungsfläche. Gemäß eines weiteren Aspekts betrifft die Erfindung eine Vorrichtung zum Auftragen eines Films auf ein flächiges, insbesondere luftundurchlässiges Substrat mit einem Zuführelement zum Zuführen des flächigen Substrats und einer Auftragsvorrichtung zum Auftragen eines Films. Schließlich betrifft die Erfindung die Verwendung eines Umlenkelements.The invention relates to a method for applying a film to a planar, in particular airtight substrate. The invention further relates to a deflection element for deflecting a planar, in particular airtight substrate with at least one guide surface formed for guiding a planar substrate and a further, with the guide surface an edge for deflecting a planar substrate enclosing guide surface. According to a further aspect, the invention relates to a device for applying a film to a flat, in particular air-impermeable substrate with a feed element for feeding the planar substrate and an applicator device for applying a film. Finally, the invention relates to the use of a deflecting element.

Bei der Herstellung von einer Vielzahl flächiger Produkttypen wie beispielsweise Klebebändern, Schutzfolien, etc. wird auf ein flächiges Substrat, beispielsweise eine transparente Kunststofffolie, ein Klebstofffilm aufgebracht. Der Klebstoff wird dazu in flüssiger Form einer Auftragsvorrichtung zugeführt, verlässt diese als zusammenhängender Film und wird in dieser Form auf das Substrat aufgebracht. Die Herstellung der Produkte ist dabei um so preiswerter, je höher die Verarbeitungsgeschwindigkeit gewählt werden kann, mit welcher der Klebstofffilm auf das Substrat aufgebracht wird.In the production of a variety of flat product types such as adhesive tapes, protective films, etc. is applied to a sheet substrate, such as a transparent plastic film, an adhesive film. The adhesive is fed to a coating device in liquid form, leaves this as a coherent film and is applied in this form to the substrate. The higher the processing speed at which the adhesive film is applied to the substrate, the cheaper the production of the products is.

Es hat sich dabei gezeigt, dass es beim Aufbringen des Klebstoffs bei allen, insbesondere bei hohen Verarbeitungsgeschwindigkeiten vermehrt zur Bildung von Lufteinschlüssen kommt. Unter der Bildung eines Lufteinschlusses wird der Effekt verstanden, dass sich zwischen dem Substrat und dem Klebstofffilm Luftblasen bilden. Derartige Lufteinschlüsse werden vom Kunden als Fabrikationsfehler aufgefasst und mindern daher die Qualität der hergestellten Produkte. Sie erschweren darüberhinaus die weitere Verarbeitung der mit dem Klebstofffilm versehenden Substrate, wie beispielsweise das Aufrollen. US 3,196,063 beschreibt das Aufbringen eines flächigen Films auf ein Substrat im Bereich einer Umlenkrolle. Das Substrat wird dabei um die Umlenkrolle herumgeführt.It has been shown that the application of the adhesive at all, especially at high processing speeds increasingly leads to the formation of air bubbles. The formation of air entrapment is understood to mean the effect that air bubbles form between the substrate and the adhesive film. Such air pockets are perceived by the customer as a manufacturing defect and therefore reduce the quality of the produced Products. In addition, they complicate the further processing of the substrates provided with the adhesive film, such as, for example, rolling up. US 3,196,063 describes the application of a flat film on a substrate in the region of a deflection roller. The substrate is guided around the deflection roller.

US 2002/0090463 A1 beschreibt ein Beschichtungsverfahren bei dem eine Bahn mittels eines Luftlagers im Bereich zwischen zwei Umlenkrollen stabilisiert wird. Vibrationen der Bahn sollen minimiert werden durch aus einer Lageroberfläche herausströmende Luft. US 2002/0090463 A1 describes a coating process in which a web is stabilized by means of an air bearing in the area between two pulleys. Vibrations of the web should be minimized by air flowing out of a bearing surface.

Es ist Aufgabe der vorliegenden Erfindung, die Bildung von Lufteinschlüssen zu vermeiden oder zumindest zu verringern, vorzugsweise auch bei hohen Verarbeitungsgeschwindigkeiten.It is an object of the present invention to avoid or at least reduce the formation of air inclusions, preferably even at high processing speeds.

Die Aufgabe wird erfindungsgemäß gelöst durch ein Verfahren mit den Merkmalen des Anspruchs 1.The object is achieved by a method having the features of claim 1.

Zum scharfen Umlenken wird erfindungsgemäß vorzugsweise ein Umlenkelement der oben genannten Art verwendet, bei dem sich durch das Umlenkelement mindestens ein Druckluftkanal zur Kante erstreckt, der in mindestens eine Austrittsöffnung im Bereich der Kante ausläuft, die so ausgebildet ist, dass aus dieser ausströmende Druckluft ein um die Kante verlaufendes Luftkissen bildet.For sharp deflection, a deflecting element of the above-mentioned type is preferably used according to the invention, in which at least one compressed air channel extends to the edge through the deflection element, which terminates in at least one outlet opening in the region of the edge, which is designed so that from this outflowing compressed air to forms the edge running air cushion.

Gemäß eines weiteren Aspektes wird die Aufgabe gelöst durch ein Umlenkelement gemäß Anspruch 11 zum Umlenken eines insbesondere luftundurchlässigen flächigen Substrats mit mindestens einer zum Führen eines flächigen Substrats ausgebildeten Führungsfläche und einer weiteren, mit der Führungsfläche eine Kante zum Umlenken eines flächigen Substrats einschließende Führungsfläche, bei dem die beiden Führungsflächen so winklig zueinander angeordnet sind, dass das Substrat während seiner Bewegung entlang der beiden Führungsflächen scharf umgelenkt wird.According to a further aspect, the object is achieved by a deflecting element according to claim 11 for deflecting a particular airtight substrate with at least one guide surface for guiding a flat substrate and another, with the guide surface an edge for deflecting a planar substrate enclosing guide surface, in which the two guide surfaces are arranged at an angle to each other, that the substrate is sharply deflected during its movement along the two guide surfaces.

Das flächige Substrat im Umlenkbereich an der Kante mittels eines Luftkissens beeinflusst. Beim Umlenken an der Kante wirkt eine Kraft auf das Substrat. Diese Kraft wirkt senkrecht auf das Bauteil, an dem die Umlenkung stattfindet, sodass es zu Reibung kommt. Um die Belastung des Substrats möglichst gering zu halten, ist es wichtig, die Reibung möglichst gering zu halten. Durch Beeinflussen des flächigen Substrats im Umlenkbereich an der Kante mittels eines Luftkissens kann die Reibung deutlich reduziert werden, was das flächige Substrat sowohl hinsichtlich mechanischer, als auch thermischer Einflüsse schont. Wird das Luftkissen aus kalter Luft gebildet, so wird das flächige Substrat zusätzlich im Umlenkbereich gekühlt. Das ist insbesondere dann vorteilhaft, wenn als Film ein Heißklebstofffilm aufgetragen wird. Im Umlenkbereich kommt das flächige Substrat dann in innigen Kontakt mit dem Heißklebstofffilm, wodurch es thermisch belastet wird. Diese thermische Belastung wird durch ein Luftkissen aus gekühlter Luft gemindert.The planar substrate in the deflection at the edge influenced by an air cushion. When deflecting at the edge, a force acts on the substrate. This force acts perpendicular to the component on which the deflection takes place, so that it comes to friction. In order to keep the load on the substrate as low as possible, it is important to keep the friction as low as possible. By influencing the planar substrate in the deflection region at the edge by means of an air cushion, the friction can be significantly reduced, which protects the planar substrate both in terms of mechanical and thermal influences. If the air cushion is formed from cold air, the planar substrate is additionally cooled in the deflection region. This is particularly advantageous if a hot-melt adhesive film is applied as the film. In the deflection region, the flat substrate then comes in intimate contact with the hot-melt adhesive film, which causes it to be thermally stressed. This thermal load is reduced by an air cushion of cooled air.

Das Substrat wird so mittels des Luftkissens beeinflusst, dass es mit der Kante nicht in unmittelbaren Kontakt gelangt. In diesem Fall kommt es nicht zu Festkörperreibung zwischen dem flächigen Substrat und dem umlenkenden Bauteil, sondern lediglich zu Fluidreibung zwischen flächigem Substrat und Luftkissen, sowie dem umlenkenden Bauteil und dem Luftkissen. Eine derartige Fluidreibung ist deutlich schwächer ausgeprägt als eine Festkörperreibung zwischen flächigem Substrat und dem umlenkenden Bauteil, so dass thermische und mechanische Belastungen vermindert werden.The substrate is so influenced by the air cushion that it does not come into direct contact with the edge. In this case, there is no solid friction between the sheet substrate and the deflecting component, but only fluid friction between the sheet substrate and air cushion, and the deflecting component and the air cushion. Such a fluid friction is significantly less pronounced than a solid friction between flat substrate and the deflecting component, so that thermal and mechanical loads are reduced.

Die Beeinflussung des flächigen Substrats im Umlenkbereich mittels eines Luftkissens erfolgt insbesondere dadurch, dass durch Luft, welche aus Austrittsöffnungen im Bereich der Kante austritt, ein Luftkissen zwischen der Kante und gegebenenfalls einem Bereich um die Kante herum einerseits und des Substrats andererseits gebildet wird. Die das Luftkissen bildende Luft sollte dabei unter mindestens einem solchen Druck stehen, dass die durch die Zuführung und Umlenkung des Substrats auf die Kante und den Kantenbereich ausgeübte Anpresskraft überwunden wird und eine möglichst vollständige Trennung des Substrats von der Kante und dem Kantenbereich erreicht wird.The influencing of the planar substrate in the deflection region by means of an air cushion is effected in particular by forming an air cushion between the edge and optionally an area around the edge on the one hand and the substrate on the other hand by air emerging from outlet openings in the region of the edge. In this case, the air forming the air cushion should be under at least such a pressure that the contact force exerted on the edge and the edge region by the feed and deflection of the substrate is overcome and a complete separation of the substrate from the edge and the edge region is achieved.

Vorteilhafte Ausführungsformen der Erfindung sind in den Unteransprüchen angegeben.Advantageous embodiments of the invention are specified in the subclaims.

Zur Ausführung des erfindungsgemäßen Verfahrens wird vorzugsweise eine Vorrichtung der eingangs genannten Art verwendet, die ein derartiges Umlenkelement umfasst. Schließlich wird die Aufgabe gelöst durch die Verwendung eines Umlenkelements der eingangs genannten Art zum Umlenken einer Substratbahn in einer Vorrichtung zum Auftragen eines Films auf die Substratbahn.For carrying out the method according to the invention, a device of the type mentioned above is preferably used which comprises such a deflection element. Finally, the object is achieved by the use of a deflection element of the aforementioned type for deflecting a substrate web in a device for applying a film to the substrate web.

Unter einem Film wird eine zusammenhängende, jedoch nicht notwendigerweise homogene Materialschicht verstanden, die von der Auftragsvorrichtung abgegeben wird. Beispiele hierfür sind dünne Heißklebstoffschichten, Folien oder Klebebänder. Als von der Auftragsvorrichtung abgegeben wird der Film auch betrachtet, wenn die Auftragsvorrichtung eine oder mehrere Substanzen abgibt, der/die auf dem Weg zum Substrat einen Film bilden.A film is understood to mean a coherent, but not necessarily homogeneous, material layer which is dispensed by the application device. Examples of these are thin hot-melt adhesive layers, films or adhesive tapes. When delivered from the applicator, the film is also viewed when the applicator dispenses one or more substances that form a film on the way to the substrate.

Das Auftragen des Films auf das flächige Substrat erfolgt erfindungsgemäß vorzugsweise so, dass der Film zeitlich vor dem scharfen Umlenken des flächigen Substrats in unmittelbarer Nähe des Substrats von der Auftragsvorrichtung abgegeben wird und zunächst eng benachbart zu dem Substrat verläuft. Der abgegebene Film und das Substrat werden dann im Umlenkbereich in unmittelbaren Kontakt gebracht, so dass eine Haftung zwischen Film und Substrat erfolgt. Nach dem Umlenkbereich befindet sich der Film als Schicht auf dem Substrat und ist mit diesem verbunden. Auf diese Weise wird durch das zugeführte flächige Substrat eine Abzugswirkung auf den von der Auftragsvorrichtung abgegebenen Film ausgeübt und durch die Zuführgeschwindigkeit des flächigen Substrats und die Abgabegeschwindigkeit des Films aus der Auftragsvorrichtung ist die Filmstärke veränderbar.According to the invention, the film is preferably applied to the planar substrate in such a way that the film is released from the application device in the immediate vicinity of the substrate before the sharp deflection of the planar substrate and initially runs closely adjacent to the substrate. The deposited film and the substrate are then brought into direct contact in the deflection region, so that adhesion takes place between the film and the substrate. After the deflection, the film is as a layer on the substrate and is connected to this. In this way, a pull-off action is exerted on the film delivered by the application device by the supplied flat substrate and the delivery speed of the flat substrate and the delivery speed of the film from the application device, the film thickness is variable.

Unter scharfem Umlenken soll in diesem Zusammenhang eine Richtungsänderung des Substrats verstanden werden, die hinsichtlich des Umlenkwinkels, des Umlenkradius und der Zuführgeschwindigkeit eine derartige Umlenkung erzielt, dass eine im Verhältnis zur Substratdicke auf kleinem Raum stattfindende Umlenkung erzielt wird. Einen wesentlichen Einfluss darauf, dass die erforderliche scharfe Umlenkung erreicht wird, hat der Umlenkwinkel, der möglichst spitz sein sollte. Der Umlenkwinkel nähert sich idealerweise 180° an, d. h. die Bewegungsrichtung des Substrats ändert sich um 180°, jedoch wird ein derart spitzer Winkel praktisch nicht umsetzbar sein, da technisch gebräuchliche Substrate eine derart starke Umlenkung bei üblichen Umlenkradien nicht unbeschadet überstehen und ein Reißen oder zumindest teilweises Beschädigen des Substrats zu befürchten ist. Einen weiteren großen Einfluss auf das Erzielen eines scharfen Umlenkens hat der Umlenkradius, der möglichst klein gewählt werden sollte. Auch hier wird die Verringerung des Umlenkradius durch die Gefahr des Beschädigens des Substrates begrenzt. Umlenkradius und Umlenkwinkel hängen in gewissem Ausmaß zusammen, d. h. bei der Wahl eines kleinen Umlenkwinkels kann ein kleinerer Umlenkradius gewählt werden als dann, wenn ein größerer Umlenkwinkel gewählt wird. Umgekehrt muss bei einem kleinen Umlenkradius ein größerer Umlenkwinkel gewählt werden als bei einem größeren Umlenkradius. Schließlich steht als dritter Einflussfaktor die Zuführgeschwindigkeit des Substrats im Zusammenhang mit dem zu wählenden Umlenkradius und dem zu wählenden Umlenkwinkel, um ein scharfes Umlenken zu erzielen. Je höher die Geschwindigkeit des flächigen Substrats im Umlenkbereich ist, desto größer muss der Umlenkwinkel und desto kleiner muss der Umlenkradius gewählt werden, um den mit der Erfindung erzielten Effekt zu erreichen.Sharp deflection should be understood in this context to be a change in the direction of the substrate which, with respect to the deflection angle, the deflection radius and the feed rate, is such Redirection achieves that in relation to the substrate thickness takes place in a small space deflection. A significant influence on the fact that the required sharp deflection is achieved, the deflection angle, which should be as pointed. The deflection angle ideally approaches 180 °, ie, the direction of movement of the substrate changes by 180 °, but such an acute angle will be virtually unworkable because technically common substrates such a strong deflection at conventional deflection radii not unscathed survive and tearing or at least partial damage to the substrate is to be feared. Another major influence on the achievement of a sharp deflection has the deflection radius, which should be chosen as small as possible. Again, the reduction of the deflection radius is limited by the risk of damaging the substrate. Deflection radius and deflection angle are related to some extent, ie when choosing a small deflection angle, a smaller deflection radius can be selected than when a larger deflection angle is selected. Conversely, with a small deflection radius, a larger deflection angle must be selected than with a larger deflection radius. Finally, as the third influencing factor, the feed rate of the substrate is related to the deflection radius to be selected and the deflection angle to be selected, in order to achieve a sharp deflection. The higher the speed of the flat substrate in the deflection region, the larger the deflection angle and the smaller the deflection radius must be selected in order to achieve the effect achieved by the invention.

Unter dem Umlenkbereich wird dabei der kleinste Bereich im Substratlaufpfad verstanden, der sich hinter der Beschichtungsvorrichtung befindet und in dessen unmittelbar anschließender Umgebung sich das Substrat in einer translatorischen Bewegung bewegt. Es handelt sich somit um den Bereich, in dem das Umlenken stattfindet und in dem sich der Krümmungsradius des Substratlaufpfads stark von den Krümmungsradien in den angrenzenden Bereichen unterscheidet. Der Substratlaufpfad ist der Pfad, den ein Teil des Substrats während des Verfahrens zurücklegt.In this case, the deflecting region is understood to mean the smallest region in the substrate running path which is located behind the coating apparatus and in whose immediately adjoining environment the substrate moves in a translatory movement. It is thus the area in which the deflection takes place and in which the radius of curvature of the substrate pathway differs greatly from the radii of curvature in the adjacent areas. The substrate trace is the path that a portion of the substrate travels during the process.

Die Erfindung bietet den Vorteil, dass die Wahrscheinlichkeit von Lufteinschlüssen beim Auftragen eines Films auf ein flächiges Substrat deutlich reduziert wird. Durch das scharfe Umlenken wird Luft, die sich möglicherweise noch zwischen dem Substrat und dem Film befindet, aus diesem Zwischenbereich herausgedrückt und/oder herausgesogen, so dass diese Luft keine Lufteinschlüsse bilden kann.The invention offers the advantage that the probability of air inclusions when applying a film to a flat substrate is significantly reduced. As a result of the sharp deflection, air that may still be present between the substrate and the film is pushed out of and / or out of this intermediate region, so that this air can not form any air pockets.

Vorteilhaft ist insbesondere, dass die Verringerung der Lufteinschlüsse auch bei hohen bis sehr hohen Zuführgeschwindigkeiten und den damit erzielbaren hohen Verarbeitungsgeschwindigkeiten erreicht wird. Die Verringerung der Lufteinschlüsse wird dabei auch dann erreicht, wenn sowohl das Substrat als auch der Film luftundurchlässig sind; in einem solchen. Fall könnten selbst kleinste Luftmengen nach dem Aufbringen des Films nicht mehr entweichen.It is particularly advantageous that the reduction of the air inclusions is achieved even at high to very high feed rates and thus achievable high processing speeds. The reduction of air inclusions is achieved even if both the substrate and the film are impermeable to air; in such a. In the event, even the smallest amounts of air could not escape after the application of the film.

Unter einer hohen Verarbeitungsgeschwindigkeit werden solche oberhalb von 150 m/min verstanden; unter einer sehr hohen Verarbeitungsgeschwindigkeit solche über 500 m/min.A high processing speed is understood to mean above 150 m / min; under a very high processing speed such over 500 m / min.

Ein weiterer Vorteil der Erfindung ist die hohe Prozesssicherheit. Bei Anlagen, die kontinuierlich betrieben werden, führen Produktionsunterbrechungen zu beträchtlichen Kosten. Die hohe Prozesssicherheit trägt damit auch zu geringeren Kosten bei.Another advantage of the invention is the high process reliability. In plants that are operated continuously, interruptions in production lead to considerable costs. The high process reliability also contributes to lower costs.

In einer bevorzugten Ausführungsform wird das scharfe Umlenken des flächigen Substrats dadurch erzielt, dass der Krümmungsradius des flächigen Substrats auf der dem Film zugewandten Seite im Umlenkbereich kleiner ist als 8mm. Der Krümmungsradius wird dabei durch einen Ausgleichskreis berechnet, der in die Kontur des Substrats im Umlenkbereich eingeschrieben wird. Durch den kleinen Krümmungsradius entsteht im Umlenkbereich ein im Vergleich zu bisherigen Verfahren großer Winkel zwischen dem Substrat und dem mit dem Substrat in Kontakt gebrachten Film. Durch diesen großen Winkel wird die Luft, die sich in diesem Bereich befindet, aus dem Bereich herausgedrängt, in dem der Film in unmittelbaren, d. h. körperlichen Kontakt mit dem Substrat gerät. So wird die Wahrscheinlichkeit von Lufteinschlüssen stark verringert.In a preferred embodiment, the sharp deflection of the planar substrate is achieved in that the radius of curvature of the planar substrate on the side facing the film in the deflection region is smaller than 8 mm. The radius of curvature is calculated by a compensation circle, which is inscribed in the contour of the substrate in the deflection region. Due to the small radius of curvature, a large angle between the substrate and the film brought into contact with the substrate arises in the deflection region in comparison to previous methods. Due to this large angle, the air in this area is forced out of the area where the film is in immediate, ie physical contact with the substrate device. This greatly reduces the chance of air pockets.

Besonders bevorzugt ist, dass der Krümmungsradius kleiner ist als 6 mm, insbesondere kleiner als 4 mm. Je kleiner der Krümmungsradius ist, desto effektiver wird die Luft aus dem Bereich zwischen Substrat und Film verdrängt und umso geringer ist damit die Wahrscheinlichkeit von Lufteinschlüssen. Unter diesem Gesichtspunkt sind somit möglichst kleine Krümmungsradien anzustreben. Andererseits ist die Belastung des Substrats dann umso größer, je kleiner der Krümmungsradius ist. Insbesondere steigt die Gefahr von Rissen oder Falten. Für jedes Substrat und jeden Film ist damit im Rahmen einer Versuchsreihe zu ermitteln, wie klein der Krümmungsradius bei einer gegebenen Verarbeitungsgeschwindigkeit gewählt werden kann, damit es nicht zu Schädigungen des Substrats kommt.It is particularly preferred that the radius of curvature is less than 6 mm, in particular less than 4 mm. The smaller the radius of curvature, the more effectively the air is displaced from the area between the substrate and the film, and the lower the probability of air inclusions. From this point of view, therefore, the smallest possible radii of curvature are desirable. On the other hand, the smaller the radius of curvature, the greater the load on the substrate. In particular, the risk of cracks or wrinkles increases. For each substrate and each film, it must be determined in the course of a series of experiments how small the radius of curvature can be chosen at a given processing speed, so that damage to the substrate does not occur.

Vorzugweise wird das Umlenken des flächigen Substrats durch Bewegen, insbesondere Ziehen des Flächensubstrats über eine Kante bewirkt. Eine Kante gestattet die Ausprägung eines kleinen Krümmungsradius mit konstruktiv einfachen Mitteln. Gleichzeitig wird so ein steifer Aufbau erreicht, der Schwingungen vermindert.Preferably, the deflection of the planar substrate by moving, in particular pulling the surface substrate over an edge is effected. An edge allows the expression of a small radius of curvature with structurally simple means. At the same time a rigid structure is achieved, which reduces vibrations.

Bevorzugt ist, dass das Umlenken des flächigen Substrats durch Bewegen, insbesondere Ziehen des Flächensubstrats über eine Kante bewirkt wird, deren Krümmungsradius kleiner ist als 3 mm, insbesondere 2 mm, vermindert um die Dicke des SubstratsIt is preferred that the deflection of the planar substrate is effected by moving, in particular pulling the surface substrate over an edge whose radius of curvature is smaller than 3 mm, in particular 2 mm, reduced by the thickness of the substrate

Vorzugsweise handelt es sich bei dem flächigen Substrat um eine transparente Folie. Bei transparenten Folien fallen Lufteinschlüsse besonderes schnell ins Auge. Aus diesem Grund ist der Einsatz des erfindungsgemäßen, Lufteinschlüsse vermindernden Verfahrens besonders günstig.Preferably, the flat substrate is a transparent film. In the case of transparent films, air pockets are particularly quick to catch the eye. For this reason, the use of the air-entrapping method according to the invention is particularly favorable.

In einer bevorzugten Ausführungsform des Verfahrens wird der Film an einem Ort in unmittelbare Nähe zu dem flächigen Substrat gebracht, der einen Abstand von 0-20 mm, insbesondere 1-10 mm vom Umlenkbereich hat. Beim Auftragen des Films auf das flächige Substrat und dem nachfolgenden Umlenken des Substrats kommt es zur Ausbildung einer Adhäsivkraft zwischen beiden Partnern, aufgrund derer sie letztlich aufeinander haften. Dabei wird Luft, die sich im Bereich zwischen Film und Substrat befindet, aus diesem Bereich u.a. durch dynamisch erzeugte lokale Luftdruckänderungen verdrängt. Wird der Abstand zwischen dem Ort, in dem der Film in unmittelbare Nähe zu dem Flächensubstrat kommt, und dem Umlenkbereich zu klein gewählt, verbleibt der Luft nicht genügend Zeit, um diesen Bereich zu verlassen. Ist der Abstand zu groß gewählt, besteht die Gefahr, dass Film und Substrat bereits vor dem Umlenken aneinander haften, so dass beim folgenden scharfen Umlenken die Luft am Entweichen gehindert wird und sich Lufteinschlüsse ausbilden können.In a preferred embodiment of the method, the film is brought into close proximity to the sheet substrate at a location having a distance of 0-20 mm, in particular 1-10 mm from the deflection. When the film is applied to the planar substrate and the subsequent deflection of the substrate results in the formation of an adhesive force between the two partners, due to which they ultimately adhere to one another. In this case, air, which is located in the area between film and substrate, from this area u.a. displaced by dynamically generated local barometric pressure changes. If the distance between the location where the film comes into close proximity to the surface substrate and the deflection area is too small, the air will not have enough time to leave this area. If the distance is too large, there is a risk that film and substrate adhere to each other before deflecting, so that the following sharp deflecting the air is prevented from escaping and can form air pockets.

Bevorzugt ist ein Verfahren, bei dem die scharfe Umlenkung des Substrats dadurch erzielt wird, dass der zwischen Zuführrichtung und -abführrichtung in der Umgebung des Umlenkbereichs eingeschlossene Winkel 40°-110°(entspricht einem Umlenkwinkel, von 140°-70°), insbesondere 50°-80° (entspricht einem Umlenkwinkel von 130°-100°), insbesondere 55°-65° (entspricht einem Umlenkwinkel von 125°-115°) beträgt. Je geringer der eingeschlossene Winkel ist, umso höher ist die Wahrscheinlichkeit, das Lufteinschlüsse vermieden werden. Mit abnehmendem Winkel steigt jedoch auch die Belastung des Substrats. Es ist damit für jedes Substrat, jeden Film und jede Verarbeitung-Geschwindigkeit in Vorversuchen zu ermitteln, wie klein dieser eingeschlossene Winkel gewählt werden kann, ohne dass es zu Schädigungen des Substrats kommt.Preference is given to a method in which the sharp deflection of the substrate is achieved by the angle enclosed between the feed direction and discharge direction in the vicinity of the deflection region being 40 ° -110 ° (corresponding to a deflection angle of 140 ° -70 °), in particular 50 ° ° -80 ° (corresponds to a deflection angle of 130 ° -100 °), in particular 55 ° -65 ° (corresponds to a deflection angle of 125 ° -115 °) is. The smaller the included angle, the higher the likelihood that air pockets will be avoided. However, as the angle decreases, so does the load on the substrate. It is thus to determine in advance for each substrate, each film and each processing speed, how small this included angle can be chosen without damaging the substrate.

Bevorzugt ist, dass das flächige Substrat als Substratbahn zugeführt wird. In diesem Fall kann das Verfahren zum Auftragen des Films als kontinuierlicher Prozess durchgeführt werden. Da hierbei etwaige Anlaufprobleme des Verfahrens weitgehend vermieden werden, insbesondere nur einmal beim starten des Prozesses auftreten, ist auf diese Art und Weise eine besonders effiziente und damit kostengünstige Produktion möglich.It is preferred that the planar substrate is supplied as a substrate web. In this case, the method of applying the film may be performed as a continuous process. Since any start-up problems of the process are largely avoided, in particular only once Start the process occur, in this way a particularly efficient and therefore cost-effective production possible.

In einer bevorzugten Ausführungsform wird das Substrat zunächst auf einer, vorzugsweise gekühlten, Leitwalze geführt, anschließend von der Leitwalze entlang einer Umlenkwalze mit im Vergleich zur Leitwalze kleinerem Durchmesser von der Leitwalze weg auf die Auftragvorrichtung zu und nach dem Umlenken auf die Leitwalze zurückgeführt. In diesem Fall wird die Geschwindigkeit, mit der der Film auf das flächige Substrat aufgetragen wird, durch die Drehgeschwindigkeit der Leitwalze bestimmt. Zusätzlich ist die Spannung des Substrats, und damit die Spannung, die im Umlenkbereich am Substrat anliegt, durch Regelung des Abstands zwischen dem Umlenkprozess und der Leitwalze sehr sensibel einstellbar. Bei hitzeempfindlichen Substraten werden dadurch, dass die Leitwalze und/oder das Umlenkelement gekühlt sind, thermische Schäden vermindert oder verhindert.In a preferred embodiment, the substrate is first guided on a, preferably cooled, guide roller, then fed back from the guide roller along a guide roller with smaller diameter compared to the guide roller of the guide roller on the applicator to and after deflecting the guide roller. In this case, the speed at which the film is applied to the sheet substrate is determined by the rotational speed of the guide roll. In addition, the voltage of the substrate, and thus the voltage applied to the substrate in the deflection, by adjusting the distance between the deflection process and the guide roller is very sensitive adjustable. In the case of heat-sensitive substrates, the fact that the guide roller and / or the deflecting element are cooled reduces or prevents thermal damage.

In einer bevorzugten Ausführungsform ist vorgesehen, dass das flächige Substrat im Umlenkbereich einem elektrostatischen Feld ausgesetzt wird, das an mindestens einer Stelle im Umlenkbereich eine Feldstärke von mehr als 5 kV/m aufweist. Versuche haben gezeigt, dass ein derartiges elektrostatisches Feld die Neigung zu Lufteinschlüssen zusätzlich verringert. Durch die Krümmung des Umlenkelements im Bereich der Kante wird eine vorteilhafte Verstärkung der Feldstärke im Umlenkbereich erzielt, da es zu einer Konzentration der Feldlinien kommt. Eine solche Feldverstärkung kann auch durch eine Verringerung des Abstands zwischen Elektrode und Umlenkelement erzielt werden.In a preferred embodiment, it is provided that the planar substrate in the deflection region is exposed to an electrostatic field which has a field strength of more than 5 kV / m at at least one point in the deflection region. Experiments have shown that such an electrostatic field additionally reduces the inclination to air inclusions. Due to the curvature of the deflecting element in the region of the edge, an advantageous reinforcement of the field strength in the deflection region is achieved since the field lines are concentrated. Such a field enhancement can also be achieved by reducing the distance between the electrode and deflecting element.

Bevorzugt ist ein Umlenkelement, das eine Kante mit einem Krümmungsradius von weniger als 5 mm, insbesondere weniger als 3 mm, insbesondere weniger als 2 mm aufweist. Wird ein flächiges Substrat über eine derartige Kante gezogen, so stellt sich dann, wenn das flächige Substrat stets Kontakt zum Umlenkelement hat, ein entsprechend kleiner Krümmungsradius auf der dem Film zugewandten Seite im Umlenkbereich ein, dessen Vorteile oben beschrieben sind.A deflecting element is preferred that has an edge with a radius of curvature of less than 5 mm, in particular less than 3 mm, in particular less than 2 mm. If a planar substrate is pulled over such an edge, then, when the planar substrate always has contact with the deflecting element, a correspondingly small radius of curvature arises on the side facing the film in the deflecting region, the advantages of which are described above.

Vorzugsweise ist die weitere, mit der Führungsfläche eine Kante einschließende Fläche, ebenfalls eine zum Führen des Flächensubstrats ausgebildete Führungsfläche.The further surface which encloses an edge with the guide surface is preferably also a guide surface designed to guide the surface substrate.

Es ist bevorzugt, dass der von den Führungsflächen in der Umgebung der Kante gebildete eingeschlossene Winkel kleiner ist als 120° insbesondere zwischen 45° und 90°, insbesondere zwischen 55° und 75° beträgt. Wenn eine oder beide Führungsflächen gekrümmt ausgeführt sind, so wird der in der Umgebung der Kante gebildete Winkel dadurch bestimmt, dass eine Ausgleichsgerade von der Länge des Durchmessers des Umlenkbereichs in die Führungsflächen eingeschrieben und der Winkel zwischen beiden Ausgleichsgeraden bestimmt wird.It is preferred that the included angle formed by the guide surfaces in the vicinity of the edge is smaller than 120 °, in particular between 45 ° and 90 °, in particular between 55 ° and 75 °. If one or both guide surfaces are curved, then the angle formed in the vicinity of the edge is determined by writing a straight line of equal length of the diameter of the deflection region into the guide surfaces and determining the angle between both equalization lines.

Der von den Führungsflächen in der Umgebung der Kante gebildete eingeschlossene Winkel stellt einen Kompromiss zwischen einem möglichst wenig unter 180° liegenden eingeschlossenen Winkel zum Vermeiden von Belastungen für das flächige Substrat und einem möglichst wenig oberhalb von 0° liegenden eingeschlossenen Winkel zum Verringern von Lufteinschlüssen dar. Versuche habe gezeigt, dass Winkel innerhalb der vorstehend angegebenen Winkelintervalle zu einer Verringerung der Neigung zur Lufteinschlussbildung führen.The included angle formed by the guide surfaces in the vicinity of the edge represents a compromise between an included angle as low as possible below 180 ° for avoiding stresses for the planar substrate and an included angle as low as possible above 0 ° for reducing air inclusions. Experiments have shown that angles within the angular intervals indicated above result in a reduction in the tendency of air entrapment.

Vorzugsweise weist zumindest eine Führungsfläche eine Balligkeit auf, insbesondere eine Balligkeit, deren Krümmungsradius zwischen 300mm und 2000mm liegt. Eine ballige Fläche kann in erster Näherung durch einen Paraboloiden beschrieben werden. Ein derartiger Paraboloid weist zwei Hauptachsen und entsprechend zwei Krümmungsradien auf. Werden diese beiden Krümmradien zwischen 300- 2000mm gewählt, so schmiegt sich das Substrat an das Umlenkelement an. Dadurch wird eine gleichmäßige Zuführung des Substrats erreicht ohne dass es zu Falten im Substrats kommt.Preferably, at least one guide surface has a crown, in particular a crown, whose radius of curvature is between 300 mm and 2000 mm. A convex surface can be described in a first approximation by a paraboloid. Such a paraboloid has two major axes and correspondingly two radii of curvature. If these two radii of curvature chosen between 300-2000 mm, so nestled the substrate to the deflection. Thereby, a uniform supply of the substrate is achieved without causing wrinkles in the substrate.

In einer bevorzugten Ausführungsform wird die Kante des Umlenkelements von einem Stab mit einem möglichst geringen Durchmesser von vorzugsweise unter 8 mm, insbesondere im Bereich von etwa 3-6mm gebildet. Dabei kann insbesondere ein drehbar gelagerter Stab eingesetzt werden, der vorzugsweise zumindest auch durch das Luftkissen gelagert ist. Einer beliebigen Durchmesserverringerung des Stabes steht die erforderliche mechanische Belastbarkeit des Stabes begrenzend entgegen. Bei allen Stabdurchmessern, insbesondere bei kleinen Stabdurchmessern kann die Lagerung des Stabes vorteilhaft mittels eines Luftkissens erreicht werden. Dieses Luftkissen wird beispielsweise innerhalb eines den Stab teilweise umschließenden Hohlraums, der den Stab gegen Herausfallen gesichert aufnimmt, mittels eines im Umlenkelement ausgebildeten Luftkanals erzeugt, der sich bis in den Hohlraum erstreckt.In a preferred embodiment, the edge of the deflecting element of a rod with the smallest possible diameter of preferably below 8 mm, in particular in the range of about 3-6mm formed. In this case, in particular a rotatably mounted rod can be used, which is preferably at least supported by the air cushion. Any reduction in the diameter of the rod is limited by the required mechanical strength of the rod limiting. With all rod diameters, especially with small rod diameters, the bearing of the rod can advantageously be achieved by means of an air cushion. This air cushion is generated, for example, within a cavity partially surrounding the rod, which receives the rod secured against falling out, by means of an air channel formed in the deflection element, which extends into the cavity.

Ist der Stab drehbar gelagert, so kommt es beim Umlenken des Substrats zu nahezu keiner Gleitreibung im Bereich der Kante, was die thermische Belastung des flächigen Substrats vermindert. Durch die Luftkissenlagerung wird die Reibung zusätzlich vermindert.If the rod is rotatably mounted, deflection of the substrate leads to virtually no sliding friction in the region of the edge, which reduces the thermal stress on the planar substrate. By the air cushion bearing friction is additionally reduced.

Bevorzugt sind die Führungsflächen als Luftkissenflächen ausgebildet. Unter einer Luftkissenfläche wird eine Fläche verstanden, die so an eine Druckluftzuführung anschließbar ist, dass sich dann, wenn ein Substrat auf der Luftkissenfläche liegt, zwischen beiden ein Luftkissen ausbildet. Hierdurch vermindert sich, wie oben bereits ausgeführt, die Reibung zwischen flächigem Substrat und Umlenkelement, so dass die thermische Belastung des Flächensubstrats verringert wird. Durch Verwendung gekühlter Luft für die Ausbildung des Luftkissens kann zudem das flächige Substrat gekühlt werden, was dessen thermische Belastung, vermindert.Preferably, the guide surfaces are designed as air cushion surfaces. An air cushion surface is understood to mean a surface which can be connected to a compressed air supply such that when a substrate lies on the air cushion surface, an air cushion forms between the two. As a result, as already mentioned above, the friction between the planar substrate and deflecting element is reduced, so that the thermal stress on the planar substrate is reduced. By using cooled air for the formation of the air cushion also the sheet substrate can be cooled, which reduces its thermal load.

Bevorzugt ist, dass die Kante von einer für Druckluft durchlässigen Oberfläche, insbesondere einem Sieb oder Gewebeelement gebildet ist. Hierdurch wird eine definierte Kante des Umlenkelements erzielt und die Ausbildung eines stabilen Luftkissens erreicht.It is preferred that the edge is formed by a permeable surface for compressed air, in particular a sieve or fabric element. As a result, a defined edge of the deflecting element is achieved and the formation of a stable air cushion is achieved.

In einer bevorzugten Ausführungsform sind im Inneren des Umlenkelements verlaufende Kanäle zur Aufnahme von Kühlmedien vorgesehen. Als Kühlmedien kommen beispielsweise Wasser, Öl, Luft und in Kühlanlagen verwendete Arbeitsgase in Betracht. Besonders bei einem heißen Klebstofffilm und/oder niedrigen Geschwindigkeiten des Substrats kann es zu thermischen Belastungen des flächigen Substrats kommen, da der heiße Klebstoff über eine lange Zeitspanne mit dem Substrat in Kontakt ist, bevor das Substrat die gekühlte Leitwalze erreicht. Durch das in den Kanälen vorhandene Kühlmedium wird zunächst das Umlenkelement und dadurch das flächige Substrat gekühlt. Befindet sich ein Luftkissen zwischen dem flächigen Substrat und dem Umlenkelement, so kühlt das Kühlmedium zudem zunächst die Luft, die das Luftkissen bildet und so mittelbar das flächige Substrat.In a preferred embodiment, extending channels are provided for receiving cooling media in the interior of the deflecting element. Suitable cooling media are, for example, water, oil, air and working gases used in refrigeration systems. Especially with a hot adhesive film and / or low speeds of the substrate, since the hot adhesive is in contact with the substrate over a long period of time before the substrate reaches the cooled guide roll, thermal stress can be placed on the sheet substrate. By means of the cooling medium present in the channels, first the deflecting element and thereby the planar substrate are cooled. If an air cushion is located between the planar substrate and the deflecting element, then the cooling medium firstly cools the air which forms the air cushion and thus indirectly the planar substrate.

In einer bevorzugten Ausführungsform weist das Umlenkelement eine fischgratförmige Oberflächenriffelung auf der Führungsfläche auf, insbesondere auf den Führungsfläche. Die Oberflächenriffelung ist dabei so angeordnet, dass das flächige Substrat bei der Bewegung entlang der Führungsfläche über die Oberflächenriffelung senkrecht zur Bewegungsrichtung auswärts gestreckt wird. Auf diese Art und Weise wird die Neigung des Substrats zur Faltenbildung vermindertIn a preferred embodiment, the deflection element has a fish-burr-shaped surface corrugation on the guide surface, in particular on the guide surface. The surface corrugation is arranged so that the planar substrate is stretched outwardly during the movement along the guide surface via the surface corrugation perpendicular to the direction of movement. In this way, the tendency of the substrate to wrinkle is reduced

In einer bevorzugten Ausführungsform ist ein feinmaschiges Gewebe auf der Führungsfläche, insbesondere den Führungsflächen vorgesehen. Das feinmaschige Gewebe dient dazu, ausströmende Druckluft so zu verteilen, dass sich ein homogenes Luftkissen ausbildet. In einem homogenen Luftkissen sind die Luftdruck-, Luftströmungs- und Lufttemperaturunterschiede innerhalb des Luftkissens so gering ausgeprägt, dass sie das Substrat nicht beeinträchtigen. Als feinmaschig wird ein Gewebe betrachtet, dass mehr als 10 Fäden/cm aufweist.In a preferred embodiment, a fine-meshed fabric is provided on the guide surface, in particular the guide surfaces. The fine-meshed fabric serves to distribute outflowing compressed air in such a way that a homogeneous air cushion is formed. In a homogeneous air cushion, the air pressure, air flow and air temperature differences within the air bag are so small that they do not affect the substrate. As a fine mesh, a tissue is considered that has more than 10 threads / cm.

In einer besonders bevorzugten Ausführungsform einer Vorrichtung zum Auftragen eines Films ist die Auftragsvorrichtung so angeordnet, dass der Punkt des Substratlaufpfads, an dem dieser einen minimalen Abstand von der Abgabeöffnung hat, zwischen 0 und 20 mm, insbesondere zwischen 1 und 10 mm vor der Kante des Umlenkelements liegt. Versuche haben gezeigt, dass hierdurch die Bildung von Lufteinschlüssen besonders effektiv verringert werden kann.In a particularly preferred embodiment of a device for applying a film, the application device is arranged such that the point of the substrate travel path at which it is at a minimum distance from the substrate Dispensing opening has, between 0 and 20 mm, in particular between 1 and 10 mm in front of the edge of the deflecting element. Experiments have shown that this can be particularly effectively reduced the formation of air bubbles.

Bei einer besonders bevorzugten Ausführungsform ist in der Umgebung des Umlenkbereichs eine Gegenelektrode so angeordnet, dass der Substratbahnpfad zwischen Umlenkelement und Gegenelektrode verläuft, und die Gegenelektrode gegen andere, insbesondere alle anderen Elemente der Vorrichtung elektrisch isoliert ist und mittels einer Spannungsquelle auf ein elektrisches Potential von betragsmäßig zumindest 1 kV gegenüber den übrigen Elementen der Vorrichtung aufladbar ist. Durch diese Maßnahme wird erreicht, dass das Umlenkelement nur gegen die Gegenelektrode auf einem elektrischen Potenzial liegt und alle anderen Bauteile potentialfrei bleiben. Zudem kann die Lage der Gegenelektrode so gewählt werden, dass der Abstand zwischen Umlenkelement und dieser Gegenelektrode klein wird, so dass das elektrische Feld besonders stark gewählt werden kann.In a particularly preferred embodiment, a counterelectrode is arranged in the vicinity of the deflection region such that the substrate web path runs between deflecting element and counterelectrode, and the counterelectrode is electrically insulated from other elements, in particular all other elements of the device, and from an electrical potential of magnitude by means of a voltage source at least 1 kV with respect to the other elements of the device is rechargeable. By this measure it is achieved that the deflecting element is only against the counter electrode at an electrical potential and all other components remain potential-free. In addition, the position of the counter electrode can be chosen so that the distance between the deflecting element and this counter electrode is small, so that the electric field can be particularly strong.

Alternativ oder ergänzend zum Vorgenannten kann vorgesehen werden, dass das Umlenkelement gegen andere, insbesondere alle anderen Elemente der Vorrichtung elektrisch isoliert ist und mittels einer Spannungsquelle auf ein elektrisches Potenzial von zumindest 1 kV gegenüber den übrigen Elementen der Vorrichtung aufladbar ist. Hierdurch wird ein elektrisches Feld zwischen dem Umlenkelement und den anderen Elementen der Maschine aufgebaut. Wird dieses elektrische Potenzial zusätzlich und mit entgegengesetztem Vorzeichen zu einem Potenzial einer Gegenelektrode aufgebracht, so lässt sich das elektrische Feld verstärken. An der Kante des Umlenkelements konzentrieren sich die Feldlinien des elektrischen Feldes und bilden dort ein besonders starkes, inhomogenes elektrisches Feld. Das elektrische Feld hat den Effekt, die Neigung zur Bildung von Lufteinschlüssen weiter zu reduzieren.Alternatively or in addition to the above, it can be provided that the deflecting element is electrically insulated from other, in particular all other elements of the device and can be charged by means of a voltage source to an electrical potential of at least 1 kV with respect to the other elements of the device. As a result, an electric field between the deflecting element and the other elements of the machine is constructed. If this electric potential is additionally applied with opposite sign to a potential of a counterelectrode, then the electric field can be amplified. At the edge of the deflecting element, the field lines of the electric field concentrate and form a particularly strong, inhomogeneous electric field there. The electric field has the effect of further reducing the tendency to form air pockets.

Im Folgenden werden zwei Ausführungsbeispiele der Erfindung anhand der Zeichnungen näher erläutert. Dabei zeigen:

Figur 1
eine schematische Darstellung einer Vorrichtung und eines Verfahrens zum Auftragen eines Klebstofffilms,
Figur 2
eine alternative Ausführungsform einer derartigen Vorrichtung bzw. eines derartigen Verfahrens,
Figur 3a
den mit A gekennzeichneten Ausschnitt aus Fig. 2,
Figur 3b
den unter Ausschnitt A liegende Abschnitt des Umlenkelements nach Fig. 2,
Figur 4
eine alternative Gestaltung der Kante eines Umlenkelements nach Figur 3a und
Figur 5a, b
schematische Darstellungen zweier Oberflächenstrukturen des Umlenkelements aus Figur 2.
In the following two embodiments of the invention will be explained in more detail with reference to the drawings. Showing:
FIG. 1
a schematic representation of an apparatus and a method for applying an adhesive film,
FIG. 2
an alternative embodiment of such a device or such a method,
FIG. 3a
the section marked A Fig. 2 .
FIG. 3b
the section lying under section A of the deflection after Fig. 2 .
FIG. 4
an alternative design of the edge of a deflection after FIG. 3a and
FIG. 5a, b
schematic representations of two surface structures of the deflection of FIG. 2 ,

Figur 1 zeigt eine Aufbring- oder eine Auftragsvorrichtung 10, die ein im Wesentlichen keilförmiges Umlenkelement 12, eine gekühlte Umlenkwalze 14, einen Auftragskopf 16, eine Gegenelektrode 18 und ein Netzteil 20 umfasst. FIG. 1 FIG. 2 shows an application device 10 comprising a substantially wedge-shaped deflection element 12, a cooled deflection roller 14, an application head 16, a counter-electrode 18 and a power supply unit 20.

Von der Umlenkwalze 14 wird eine aus Polypropylen (PP), Polyethylen (PE) oder Polyethylentherephthalat (PET) bestehende, 20-100µm dicke Substratbahn 22 mit einer Geschwindigkeit von bis zu 600 m/min in Richtung auf den Auftragskopf 16 zu umgelenkt. Die Substratbahn 22 verläuft entlang einer Zuführ-Führungsfläche 24 des Umlenkelements 12, wird an einer Kante 26 des Umlenkelements 12 scharf umgelenkt und läuft dann entlang einer Abführ-Führungsfläche 28 in Richtung des Pfeils P ab.From the guide roller 14, a 20-100μm thick substrate web 22 consisting of polypropylene (PP), polyethylene (PE) or polyethylene terephthalate (PET) is deflected in the direction of the application head 16 at a speed of up to 600 m / min. The substrate web 22 runs along a feed guide surface 24 of the deflecting element 12, is deflected sharply at an edge 26 of the deflecting element 12 and then runs along a discharge guide surface 28 in the direction of the arrow P.

Die Umlenkwalze 14 ist dabei als-Kühlwalze ausgebildet, wobei die Anschlüsse für das Kühlmedium nicht eingezeichnet sind. Durch die Kühlung wird die Substratbahn 22 gfs. bis auf Taupunkt gekühlt. Anschließend wird sie entlang der Zuführ- Führungsfläche 24 geführt und gelangt in die Umgebung des Auftragskopfs 16.The guide roller 14 is designed as a cooling roller, wherein the connections for the cooling medium are not shown. By cooling the substrate web 22 gfs. cooled to dew point. Subsequently, it is guided along the feed guide surface 24 and enters the environment of the application head 16.

Der Auftragskopf 16 wird über eine Klebstoffzuleitung 30 mit flüssigem Heißklebstoff versorgt, der eine Temperatur von 150°C hat. Diese Temperatur ist in Abhängigkeit der Materialeigenschaften des Substrats und des Heißklebsztoffs einzustellen. Der Heißklebstoff verlässt den Auftragskopf 16 durch eine Austrittsöffnung 32 in Form eines dünnen, transparenten Klebstofffilms 34. Der Auftragskopf und seine Austrittsöffnung sind so zu dem Umlenkelement angeordnet, daß der Klebstofffilm 34 etwa parallel zur Abführrichtung des Substrats und um einen mit x gekennzeichneten Versatz von der Kante 26 des Umlenkelements 12 in Zuführrichtung beabstandet austritt. Der Klebstofffilm 34 kommt vorzugsweise an einem Ort in unmittelbare Nähe mit der Substratbahn 22, der sich in Laufrichtung der Substratbahn vor dieser Kante befindet. An diesem Ort wird zunächst eine Annäherung auf einen sehr geringen Abstand zwischen Substratbahn 22 und Klebstofffilm 34 erreicht, jedoch noch kein unmittelbarer Kontakt.The application head 16 is supplied via an adhesive supply line 30 with liquid hot melt adhesive, which has a temperature of 150 ° C. This temperature is depending on the material properties of the substrate and the Heißklebsztoffs set. The hot-melt adhesive leaves the applicator head 16 through an outlet opening 32 in the form of a thin, transparent adhesive film 34. The applicator head and its outlet opening are arranged relative to the deflecting element such that the adhesive film 34 is approximately parallel to the discharge direction of the substrate and offset by Edge 26 of the deflecting element 12 emerges spaced apart in the feed direction. The adhesive film 34 is preferably in a location in close proximity with the substrate web 22, which is in the direction of the substrate web in front of this edge. At this location, an approximation to a very small distance between substrate web 22 and adhesive film 34 is initially achieved, but still no direct contact.

Nachdem der Klebstofffilm 34 und die Substratbahn 22 miteinander in unmittelbare Nähe gekommen sind, werden beide dadurch scharf umgelenkt, dass sie gemeinsam über die Kante 26 gezogen werden. Dazu wird von einer hier nicht eingezeichneten Vorrichtung eine Zugkraft auf die Substratbahn 22 ausgeübt, die in Richtung des Pfeils P wirkt. Der Winkel a zwischen den Zuführ-Führungsfläche 24 und der Abführ- Führungsfläche 28 beträgt 60°. Der Krümmungsradius der Substratbahn 22 beträgt in dem Moment, in dem sie über die Kante 26 gezogen wird, 2mm. Entsprechend beträgt der Krümmungsradius des Substratbahnlaufpfads an der Kante 26 ebenfalls 2mm. Durch das scharfe Umlenken gelangen die Substratbahn 22 und der Klebstofffilm 34 in unmittelbaren Kontakt und haften lufteinschlussfrei aneinander.After the adhesive film 34 and the substrate web 22 have come into close proximity with each other, both are sharply deflected by being pulled together over the edge 26. For this purpose, a tensile force is exerted on the substrate web 22 by a device, not shown here, which acts in the direction of the arrow P. The angle α between the feed guide surface 24 and the discharge guide surface 28 is 60 °. The radius of curvature of the substrate web 22 is 2 mm at the moment it is pulled over the edge 26. Accordingly, the radius of curvature of the substrate web path at the edge 26 is also 2mm. Due to the sharp deflection, the substrate web 22 and the adhesive film 34 come into direct contact and adhere to each other without air entrapment.

Das Umlenkelement 12 ist geerdet. In Verlängerung der Zuführ Führungsfläche 24 und seitlich auf die Abführ-Führungsfläche 28 hin verschoben befindet sich gegenüber der AbführFührungsfläche 28 die Gegenelektrode 18. Diese wird durch einen Generator 20 gegenüber dem elektrischen Nullniveau auf eine konstante Hochspannung von 10-30 kV aufgeladen. Dadurch bildet sich zwischen dem Umlenkelement 12 und der Gegenelektrode 18 ein elektrisches Feld E aus, das insbesondere an der Kante 26 aufgrund deren Krümmung besonders groß ist, da sich hier die elektrischen Feldlinien konzentrieren.The deflecting element 12 is grounded. In extension of the feed guide surface 24 and laterally displaced toward the discharge guide surface 28 is opposite the AbführFührungsfläche 28, the counter electrode 18. This is charged by a generator 20 relative to the electrical zero level to a constant high voltage of 10-30 kV. As a result, an electric field E forms between the deflection element 12 and the counterelectrode 18, which is particularly large at the edge 26 in particular because of its curvature, since the electric field lines concentrate here.

Figur 2 zeigt eine alternative Ausführungsform der Aufbringvorrichtung 10. Die Substratbahn 22 läuft dabei zunächst auf einer gfs. bis zum Taupunkt gekühlten Leitwalze 38, die sich in Richtung des Pfeils P dreht. Von der Leitwalze 38 wird die Substratbahn 22 durch die Umlenkwalze 14 umgelenkt und verläuft entlang der Zuführ-Führungsfläche 24 des Umlenkelements 12, um die Kante 26 herum und entlang der AbführFührungsfläche 28, von wo aus sie wiederum auf die Leitwalze 38 gelangt. FIG. 2 shows an alternative embodiment of the applicator 10. The substrate web 22 initially runs on a gfs. cooled to dew point guide roller 38 which rotates in the direction of arrow P. From the guide roller 38, the substrate web 22 is deflected by the guide roller 14 and extends along the feed guide surface 24 of the deflecting element 12, around the edge 26 and along the AbführFührungsfläche 28, from where it in turn reaches the guide roller 38.

Das Umlenkelement 12 hat im Wesentlichen einen dreiecksförmigen Querschnitt, wobei jedoch die längste Seite, die der Leitwalze 38 zugewandt ist, konkav ausgebildet ist und einen Krümmungsradius aufweist, der dem Radius der Leitwalze 38 entspricht.The deflecting element 12 has a substantially triangular cross-section, but the longest side facing the guide roller 38 is concave and has a radius of curvature which corresponds to the radius of the guide roller 38.

Die beiden anderen Seitenflächen des Umlenkelements 12 sind leicht ballig ausgeführt. Dabei verläuft eine Hauptachse des jeweiligen Schmiegeparaboloids parallel zur Drehachse der Leitwalze 38, die andere Hauptachse verläuft senkrecht dazu und entlang des Laufpfades 22. In beiden Hauptrichtungen ist der Krümmungsradius größer als jener der Leitwalze 38 und beträgt beispielsweise 1000mm bezüglich der Hauptachse, die parallel zur Drehachse der Leitwalze 38 verläuft und ebenfalls 1000mm bezüglich der anderen Hauptachse.The two other side surfaces of the deflecting element 12 are slightly convex. In this case, a major axis of the respective Schmiebparaboloids parallel to the axis of rotation of the guide roller 38, the other major axis perpendicular thereto and along the barrel path 22. In both main directions, the radius of curvature is greater than that of the guide roller 38 and is for example 1000mm with respect to the major axis, parallel to the axis of rotation the guide roller 38 runs and also 1000mm with respect to the other major axis.

Zwischen der Substratbahn 22 und dem Umlenkelement 12 befindet sich ein Luftkissen 40. Zum Aufbau dieses Luftkissens 40 ist im Inneren des Umlenkelements 12 ein Hohlraum 42 vorgesehen. Dieser steht über einen hier nicht eingezeichneten Anschluss in Verbindung mit einer ebenfalls nicht eingezeichneten Druckluftquelle, so dass der Hohlraum 42 mit Druckluft gefüllt ist. Durch eine Vielzahl von Bohrungen 44 gelangt die Druckluft aus dem Hohlraum 42 an die Oberfläche des Umlenkelements 12. Dort tritt sie durch ein feinmaschiges Gewebe 46, das einen Teil des Umlenkelements 12 darstellt, nach außen und bildet zwischen der Substratbahn 22 und dem Umlenkelement 12 das Luftkissen 40.An air cushion 40 is located between the substrate web 22 and the deflecting element 12. In order to build up this air cushion 40, a cavity 42 is provided in the interior of the deflecting element 12. This is connected via a connection not shown here in connection with a likewise not shown compressed air source, so that the cavity 42 is filled with compressed air. Through a plurality of holes 44, the compressed air from the cavity 42 reaches the surface of the deflecting 12. There it passes through a fine mesh fabric 46, which is part of the deflecting element 12, to the outside and forms between the substrate web 22 and the deflecting element 12th Air cushion 40.

Von der Kante 26 verläuft ein Schlitz 48 bis in den Hohlraum 42. Durch den Schlitz 38 tritt im Bereich der Kante 26 ebenfalls Druckluft aus und bildet ein Luftkissen um die Kante 26 aus.From the edge 26, a slot 48 extends into the cavity 42. Through the slot 38 occurs in the region of the edge 26 also compressed air and forms an air cushion around the edge 26 from.

Im Bereich der Kante 26 wird die Substratbahn 22 im Umlenkbereich scharf umgelenkt. Der Umlenkbereich 36 ist dabei der Bereich des Substratbahnlaufpfads, an dem sich die Krümmung stark ändert: Im Bereich der Zuführ-Führungsfläche 24 entspricht der Krümmungsradius der Substratbahn 22 im Wesentlichen der Krümmung der Zuführ-Führungsfläche 24, entsprechend ist der Krümmungsradius des Substratbahnlaufpfads im Bereich der AbführFührungsfläche 28 im Wesentlichen gleich deren Krümmungsradius. Zwischen beiden Bereichen liegt der Umlenkbereich 36, in dem der Krümmungsradius statt 1000mm nunmehr lediglich 1-6mm beträgt.In the region of the edge 26, the substrate web 22 is deflected sharply in the deflection region. In this case, the deflection region 36 is the region of the substrate web running path at which the curvature changes greatly. In the region of the feed guide surface 24, the radius of curvature of the substrate web 22 essentially corresponds to the curvature of the feed guide surface 24. Correspondingly, the radius of curvature of the substrate web run path is in the region of AbführFührungsfläche 28 substantially equal to the radius of curvature. Between two areas of the deflection region 36, in which the radius of curvature instead of 1000mm is now only 1-6mm.

Von dem Auftragskopf 16 wird flüssiger Heißklebstoff in Form eines Klebstofffilms 34 auf die Substratbahn 22 abgegeben. Der Klebstofffilm 34 kommt dabei in unmittelbare Nähe mit der Substratbahn 22, nicht jedoch in unmittelbaren Kontakt. Im Bereich zwischen Klebstofffilm 34 und Substratbahn 22 befindet sich Luft. Werden Klebstofffilm 34 und Substratbahn 22 im Umlenkbereich 36 scharf umgelenkt, so wird der Klebstofffilm in unmittelbaren Kontakt mit der Substratbahn gebracht und dabei diese Luft entgegen der Bewegungsrichtung der Substratbahn aus diesem Bereich herausgedrückt. Dadurch haftet der Klebstofffilm 34 danach ohne Lufteinschlüsse auf der Substratbahn 22 an.From the application head 16 liquid hot adhesive in the form of an adhesive film 34 is discharged onto the substrate web 22. The adhesive film 34 comes in the immediate vicinity of the substrate web 22, but not in direct contact. In the area between the adhesive film 34 and substrate web 22 is air. If adhesive film 34 and substrate web 22 are deflected sharply in the deflection region 36, then the adhesive film is brought into direct contact with the substrate web and this air is pressed out of this region counter to the direction of movement of the substrate web. As a result, the adhesive film 34 then adheres to the substrate web 22 without air inclusions.

Aufgrund des Wärmeeintrags durch den Heißklebstoff, der den Klebstofffilm 34 bildet, kommt es zunächst zu einer Erwärmung der Substratbahn 22 im Umlenkbereich. Um einer möglichen thermischen Schädigung vorzubeugen, wird die im Hohlraum 42 befindliche Druckluft und das Umlenkelement gekühlt. Dazu sind ein oder mehrere Kühlmittelkanäle 52 im Umlenkelement 12 vorgesehen. Die Kühlmittelkanäle 52 verlaufen dabei parallel zu den Drehachsen von Leitwalze 38 und Umlenkwalze 14. Um die Wärmeübertragung von Druckluft auf das Kühlmedium zu verbessern ist das Umlenkelement aus gut leitendem Material gefertigt.Due to the heat input by the hot melt adhesive, which forms the adhesive film 34, there is initially a heating of the substrate web 22 in the deflection region. In order to prevent a possible thermal damage, the compressed air in the cavity 42 and the deflecting element is cooled. For this purpose, one or more coolant channels 52 are provided in the deflecting element 12. The coolant channels 52 extend parallel to the axes of rotation of the guide roller 38 and deflecting roller 14. In order to improve the heat transfer of compressed air to the cooling medium, the deflecting element is made of highly conductive material.

Bei einer alternativen Ausführungsform ist das Umlenkelement oder Oberflächenäbschnitte des Umlenkelements aus einem Sintermetall hergestellt. Sintermetalle eignen sich einerseits dazu, um gleitfähige Oberflächen auszubilden. Andererseits kann bei Sintermetallen eine offene Porosität eingestellt werden, die bei der erfindungsgemäßen Anwendung vorteilhaft zur Ausbildung des Luftpolsters verwendet werden kann. So ist es möglich, die Gleitbahnen des Umlenkelements zumindest teilweise aus einem offen porösen Sintermetall herzustellen und dieses Sintermetall mit einem Druckluftanschluss zu verbinden, so dass aus den Poren des Sintermetalls unter Druck stehende Luft austritt und zwischen Substrat und der Oberfläche des Sintermetalls das Luftpolster ausgebildet wird.In an alternative embodiment, the deflecting element or Oberflächenäbschnitte the deflecting element is made of a sintered metal. On the one hand, sintered metals are suitable for forming lubricious surfaces. On the other hand, in the case of sintered metals, an open porosity can be set which, in the application according to the invention, can be advantageously used to form the air cushion. Thus, it is possible to produce the slideways of the deflecting element at least partially from an openly porous sintered metal and to connect this sintered metal to a compressed air connection, so that air emerging from the pores of the sintered metal exits and the air cushion is formed between the substrate and the surface of the sintered metal ,

Die Zugspannung, unter der die Substratbahn 22 auf ihrem Weg entlang des Umlenkelements 12 steht, wird über den Abstand des Umlenkelements 12 vom Mittelpunkt der Leitwalze 38 geregelt, der die Führungsgröße darstellt. Als Regelgröße wird beispielsweise der Abstand des Substrats 22 von der Kante 26 oder die Häufigkeit von Lufteinschlüssen verwendet.The tension under which the substrate web 22 is on its way along the deflecting element 12 is controlled by the distance of the deflecting element 12 from the center of the guide roller 38, which represents the reference variable. As a controlled variable, for example, the distance of the substrate 22 from the edge 26 or the frequency of trapped air is used.

Figur 3a zeigt eine alternative Ausführungsform eines Umlenkelements 12. Der vom Hohlraum 42 zur Kante 26 verlaufende Schlitz 48 endet in einem Hohlraum 54, der von einem sehr feinmaschigen Sieb 56 zur Kante 26 hin begrenzt wird. Das Gewebe 46 erstreckt sich von der Zuführ-Führungsfläche 24 über das Sieb 56 hinweg entlang der AbführFührungsfläche 28. Je nachdem, wie weit sich das Sieb 56 über die Kante 26 erstreckt, kann das Luftkissen 40 im Bereich der Kante in seiner Stärke variiert werden. Alternativ zum Sieb ist auch ein Lochblech o. ä. einsetzbar. FIG. 3a shows an alternative embodiment of a deflecting 12. The extending from the cavity 42 to the edge 26 slot 48 terminates in a cavity 54 which is bounded by a very fine mesh screen 56 to the edge 26 out. The web 46 extends from the feed guide surface 24 across the wire 56 along the discharge guide surface 28. Depending on how far the wire 56 extends over the edge 26, the air bag 40 may be varied in thickness in the region of the edge. As an alternative to the sieve, a perforated plate or similar can be used.

Figur 3b zeigt die Befestigung des Gewebes 46 mittels Klemmsteinen 58, die das Gewebe in einer Ausnehmung 60 festklemmen und dadurch verhindern, dass es von der aus dem Inneren des Umlenkelements ausströmenden Druckluft abgehoben wird. Die Klemmsteine 58 sind mit in dieser Ansicht nicht sichtbaren Senkkopfschrauben befestigt. FIG. 3b shows the attachment of the fabric 46 by means of clamping blocks 58, which clamp the tissue in a recess 60 and thereby prevent it from being lifted off by the air flowing out of the interior of the deflecting compressed air. The clamping blocks 58 are attached with not visible in this view countersunk screws.

Fig. 4 zeigt eine alternative Ausführungsform der Kante 26 des Umlenkelements 12. Zwischen der Zuführ-Führungsfläche 24 und der Abführ-Führungsfläche 28 ist ein Stab 62 vorgesehen, der durch hier nicht eingezeichnete Kugellager drehbar gelagert ist. Der Stab 62 weist einen Durchmesser von 2mm auf und ist so positioniert, dass annähernd dessen halber Umfang über die Verlängerungen von Zuführ-Führungsfläche 24 und Abführ-Führungsfläche 28 hinausragt. Fig. 4 shows an alternative embodiment of the edge 26 of the deflecting 12. Between the feed guide surface 24 and the discharge guide surface 28, a rod 62 is provided which is rotatably supported by ball bearings not shown here. The rod 62 has a diameter of 2 mm and is positioned so that approximately half of its circumference protrudes beyond the extensions of the feed guide surface 24 and the discharge guide surface 28.

Fig. 5a zeigt schematisch eine Ausführungsform der Oberflächenbeschaffenheit der Zuführ-Führungsfläche 24 und/oder der Abführ-Führungsfläche 28. Auf der Führungsfläche sind linear verlaufende Riffel 64 ausgebildet, also Erhebungen, die sich über die Grundfläche der Zuführ-Führungsfläche erheben. Diese Riffel 64 sind zur Reibungsminderung mit einem Chromüberzug versehen und sind fischgratförmig bzw. V-förmig so angeordnet, so dass je zwei Riffel in einem Punkt zusammenlaufen. Alle derartigen Punkte liegen auf einer Geraden, die parallel zu den Seiten der Führungsfläche verläuft. Fig. 5a schematically shows an embodiment of the surface finish of the feed guide surface 24 and / or the discharge guide surface 28. On the guide surface linearly extending corrugations 64 are formed, so elevations that rise above the base surface of the feed guide surface. These corrugations 64 are provided with a chromium coating for friction reduction and are arranged in the form of a fishbone or V-shaped so that two corrugations converge at a point. All such points lie on a straight line that runs parallel to the sides of the guide surface.

Die hier nicht eingezeichnete Substratbahn bewegt sich in Richtung des Pfeils P. Durch die Anordnung der Riffeln 64 wird die Substratbahn beim Gleiten auf der Führungsfläche auseinander gezogen, so dass eine Neigung der Substratbahn zur Faltenbildung in vermindert wird.The substrate web, not shown here, moves in the direction of the arrow P. The arrangement of the corrugations 64 pulls the substrate web apart when sliding on the guide surface, so that an inclination of the substrate web for wrinkling is reduced.

Fig. 5b zeigt schematisch eine Draufsicht auf die Zuführ-Führungsfläche 24, die mit dem Gewebe 46 bespannt ist. Das Gewebe 46 weist eine Leinwandbindung und eine Fadendichte von 10 Fäden/cm auf. Unterhalb des Gewebes 46 und somit in der Draufsicht nicht sichtbar enden die Stichbohrungen 44, aus denen Druckluft austritt. Durch das Gewebe 46 wird die Druckluft so verteilt, dass sich ein homogenes Luftkissen ausbildet. Fig. 5b schematically shows a plan view of the feed guide surface 24, which is covered with the fabric 46. The fabric 46 has a plain weave and a thread density of 10 threads / cm. Below the fabric 46 and thus not visible in the plan view end the tap holes 44 from which compressed air emerges. Through the fabric 46, the compressed air is distributed so that forms a homogeneous air cushion.

Claims (25)

  1. A method of applying a film (34) to a planar, in particular air-impermeable substrate (22), comprising the following steps:
    - feeding the planar substrate (22) in a feed direction towards an application head (16).
    - applying a film (34) delivered by the application head (16) on to the planar substrate (22), characterized by
    - sharply deflecting the planar substrate together with the film (34) which is in contact therewith in a deflection region (36) into a discharge direction which is different from the feed direction, in such a way that the radius of curvature of the planar substrate on the side towards the film (34) in the deflection region (36) is less than 8 mm
    - forming an air cushion (40) in the deflection region (36) between the edge (26) and the planer substrate (22), so that the planar substrate (22) does not come into direct contact with the edge (26).
  2. A method according to claim 1 characterised in that the radius of curvature is less than 6 mm, in particular less than 4 mm, in particular less than 2 mm.
  3. A method according to one of the preceding claims characterised in that sharply deflecting the planar substrate (22) is effected by pulling the substrate over a rotatably mounted cylindrical bar of a radius corresponding to the radius of curvature.
  4. A method according to one of the preceding claims characterised in that sharply deflecting the planar substrate (22) is implemented by moving the planar substrate (22) and the film (24) over an edge (26) in the deflection region (36)
    so that the substrate (22) and the film (24) come into direct contact and adhere to each other.
  5. A method according to claim 1 characterised in that sharply deflecting the planar substrate (22) prevents air inclusions between the substrate (22) and the film (26).
  6. A method according to one of the preceding claims characterised in that the film (34) is brought into immediate proximity with respect to the planar substrate (22) at a location which is at a spacing of 0 - 20 mm, in particular 1 - 10 mm from the deflection region (36).
  7. A method according to one of the preceding claims characterised in that the planar substrate (22) is so deflected that the angle included between the feed direction and the discharge direction in the region surrounding the deflection region (36) is 40° - 110°, in particular 50° - 80°, in particular 55° - 65°.
  8. A method according to one of the preceding claims characterised in that the planar substrate (22) is firstly guided on a preferably cooled guide roller (38), it is then guided from the guide roller (38) along a deflection roller (14) of a smaller diameter in comparison with the guide roller (38) away from the guide roller (38) to the application head (16) and after deflection is guided back on to the guide roller (38).
  9. A method according to one of the preceding claims characterised in that the planar substrate (22) is subjected in the deflection region (36) to an electrostatic field which is of a field strength of more than 5 kV/m at at least one location in the deflection region (36).
  10. A method according to one of the preceding claims characterised in that the planar substrate (22) is cooled in the feed region and/or in the deflection region (36).
  11. A deflection element for deflecting a film and a substrate and in particular air-impermeable planar substrate (22):
    characterized by a first guide surface (24) adapted to guide a planar substrate and a second guide surface (28) which together form an edge (26) for the sharp deflection of the film and the planar substrate, wherein the edge (26) has a radius of curvature of less than 8 mm, and
    at least one compressed air passage (48) extending through the deflection element (12) to the edge (26) and at least one outlet opening connected to the air passage (48) in the region of the edge (26) such that compressed air flowing from the outlet forms an air cushion (40) extending around the edge (26).
  12. A deflection element according to claim 11, comprising
    wherein the two guide surfaces (24, 28) are so arranged in mutually angular relationship that the substrate and film are sharply deflected during movement over edge (26) causing the substrate (22) and film (34) to come into direct contact and adhere to each other preventing air inclusions.
  13. A deflection element according to claim 11 or 12 characterised in that the edge (26) has a radius of curvature of less than 6 mm, in particular less than 4 mm, in particular less than 2mm.
  14. A deflection element according to one of claims 11 to 13 characterised in that the included angle formed by the guide surfaces (24, 28) in the region surrounding the edge (26) is less than 120°, in particular 45° to 90°, in particular 55° to 75°.
  15. A deflection element according to one of claims 11 to 14 characterised in that at least one guide surface (24, 28) has a camber in particular such that the camber has a radius of curvature of between 300 mm and 2000 mm.
  16. A deflection element according to one of claims 11 to 15 characterised in that the edge (26) is formed by a bar (62) of a diameter of less than 8 mm. wherein the bar (62) is in particular rotatably mounted and is preferably at least also mounted through the air cushion (40).
  17. A deflection element according to one of claims 11 to 16 characterised in that the guide surfaces (24, 28) are in the form of air cushion surfaces.
  18. A deflection element according to one of claims 11 to 17 characterised in that the edge (26) is formed by a surface which is permeable for compressed air, in particular a mesh (56) or cloth element.
  19. A deflection element according to one of claims 11 to 18 characterised by passages (56) extending in the interior for receiving cooling medium.
  20. A deflection element according to one of claims 11 to 19 characterised by fishbone-shaped surface grooving (64) in the guide surfaces (24, 28).
  21. A deflection element according to one of claims 11 to 20 characterised by a fine-mesh cloth (46) on the guide surfaces (24, 28).
  22. Apparatus for applying a film to a planar, in particular air-impermeable substrate (22), comprising
    a roller (14, 38) for feeding the planar substrate (22), and
    an application head (16) for applying a film (34),
    characterised by a deflection element (12) according to one of claims 15 to 26.
  23. Apparatus according to claim 22 characterised in that the applicator device (16) is positioned from a minimum of 0 to 20 mm, in particular between 1 and 8 mm, before the edge (26) of the deflection element (12).
  24. Apparatus according to one of claims 22 or 23 characterised in that the deflection element (12) is electrically insulated in relation to other and in particular all other elements of the apparatus and is chargeable by means of a voltage source (20) to an electrical potential of a value of at least 1 kV, preferably at least 5 kV, with respect to the other elements of the apparatus.
  25. Apparatus according to one of claims 22 to 24 characterised in that a counterpart electrode (18) is arranged in the region around the deflection region (36) in such a way that the substrate web path extends between the deflection element (12) and the counterpart electrode (18) and is electrically insulated in relation to other and in particular all other elements of the apparatus and is chargeable by means of a voltage source (20) to an electrical potential of a value of at least 1 kV, preferably at least 5 kV, with respect to the other elements of the apparatus.
EP05729869A 2004-04-16 2005-04-01 Method for applying a film to a planar substrate, deflecting element and device for applying a film to a planar substrate Expired - Fee Related EP1744835B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE102004019048A DE102004019048A1 (en) 2004-04-16 2004-04-16 Method for applying a film to a flat substrate, deflecting element and device for applying a film to a flat substrate
PCT/EP2005/003444 WO2005099911A2 (en) 2004-04-16 2005-04-01 Method for applying a film to a planar substrate, deflecting element and device for applying a film to a planar substrate

Publications (2)

Publication Number Publication Date
EP1744835A2 EP1744835A2 (en) 2007-01-24
EP1744835B1 true EP1744835B1 (en) 2011-06-15

Family

ID=34963778

Family Applications (1)

Application Number Title Priority Date Filing Date
EP05729869A Expired - Fee Related EP1744835B1 (en) 2004-04-16 2005-04-01 Method for applying a film to a planar substrate, deflecting element and device for applying a film to a planar substrate

Country Status (4)

Country Link
US (1) US7691448B2 (en)
EP (1) EP1744835B1 (en)
DE (1) DE102004019048A1 (en)
WO (1) WO2005099911A2 (en)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1895051B1 (en) * 2006-09-01 2009-04-29 Mitsubishi HiTec Paper Bielfeld GmbH Curtain coating process and apparatus therefor
FR2931384B1 (en) * 2008-05-22 2010-05-28 Bostik Sa MULTILAYER FILMS FOR FLEXIBLE PACKAGING
ITBG20110016A1 (en) * 2011-05-23 2012-11-24 I C I Srl Italiana Commerciale Ind Ustriale REALIZED PROCEDURE OF HIGH SPIGULATED LAMINATED PANELS FOR DOORS AND FURNITURE, AND OBJECTED PANELS OBTAINED.
FR2993543B1 (en) 2012-07-19 2014-08-15 Bostik Sa MULTILAYER FILM FOR FLEXIBLE PACKAGING
JP6717191B2 (en) * 2014-04-18 2020-07-01 株式会社ニコン Film forming apparatus, substrate processing apparatus, and device manufacturing method
CN105694750A (en) * 2016-02-03 2016-06-22 河北华夏实业有限公司 Production method of novel high-temperature-resistant polyvinyl chloride adhesive tape

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3196063A (en) * 1962-03-28 1965-07-20 Int Paper Co Coated paper and method of producing the same
US3788271A (en) * 1972-04-14 1974-01-29 Perma Glas Mesh Corp Apparatus for applying pressure sensitive adhesive to glass fiber mesh material
US5591496A (en) * 1990-11-20 1997-01-07 Linpac Plastics International Limited Method of manufacturing composite sheet materials
DE19534702A1 (en) * 1995-09-19 1997-03-20 Reifenhaeuser Masch Process for producing a composite web from a nonwoven nonwoven web and a one-sided coating from a plastic film
DE19634448C2 (en) * 1996-08-26 1999-06-24 Voith Sulzer Papiermasch Gmbh Method and device for applying a liquid or pasty medium to a running material web
ES2160381T3 (en) 1997-05-02 2001-11-01 Rasselstein Hoesch Gmbh PROCEDURE AND DEVICE FOR COVERING WITH PLASTIC METAL FLEXES BY DIRECT EXTRUSION.
US6368675B1 (en) * 2000-04-06 2002-04-09 3M Innovative Properties Company Electrostatically assisted coating method and apparatus with focused electrode field

Also Published As

Publication number Publication date
US20080166487A1 (en) 2008-07-10
EP1744835A2 (en) 2007-01-24
US7691448B2 (en) 2010-04-06
DE102004019048A1 (en) 2005-11-10
WO2005099911A3 (en) 2006-06-29
WO2005099911A2 (en) 2005-10-27

Similar Documents

Publication Publication Date Title
EP1488909B1 (en) Take-off apparatus for tubular plastic film extrusion unit and method of manufacturing a tubular plastic film
EP0212232B1 (en) Method and apparatus for the continuous production of thermoplastic sheets
EP1744835B1 (en) Method for applying a film to a planar substrate, deflecting element and device for applying a film to a planar substrate
EP1492672B1 (en) Device and method for the production of composite materials
EP1488910A1 (en) Method and apparatus for manufacturing a thermoplastic film
DE202017006956U1 (en) Device for laminating a substrate with a thermoplastic coating material
DE1779318B2 (en) DEVICE FOR DEPOSITING A FILM OF FILM-FORMING MATERIAL
EP1711331A1 (en) Method and device for longitudinal drawing of a film web
EP3038733A2 (en) Filter material, filter element, and a method and device for producing a filter material
DE3907846B4 (en) Coating apparatus and method for applying a coating medium to a continuous flexible carrier
EP1429902B1 (en) Method for the production of bearing materials and use of bearing materials produced by this method
EP3038732A2 (en) Filter material, filter element, and a method and device for producing a filter material
DE19653749A1 (en) Device for applying a film emerging from a slot die to a rotating take-off roller
EP3520989A1 (en) Method and device for manufacturing a plastic film
DE102005038730A1 (en) Improved airflow at the film bubble
DE3100101C2 (en) Device for applying a thin layer of a coating material to a material web
DE102008035737A1 (en) Lay-on roller for lying of form of film in impression roller, particularly cooling and casting roller, has flexible surface with anti-stick-effect
EP2117841A1 (en) Laminating process and apparatus for applying an adhesive-composition film to a web-like substrate
DE19938165A1 (en) Method and device for guiding a material web
DE19605951C2 (en) Smoothing unit for the production of sheets and foils made of thermoplastic plastic smoothed on both sides
DE2433224B2 (en) DEVICE FOR IMPROVING THE ADHESION OF PLASTIC FILMS
EP1587662B1 (en) Take-off unit
DE2114846C2 (en) Device for guiding and pressing a thermoplastic film web onto a moving quenching surface
DE19826063A1 (en) Assembly to cool a heated web on leaving a calendar
DE3729985A1 (en) METHOD AND DEVICE FOR APPLYING A FILM FROM A PLASTIC MEL TO A MOVING COOLING SURFACE

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU MC NL PL PT RO SE SI SK TR

AX Request for extension of the european patent

Extension state: AL BA HR LV MK YU

17P Request for examination filed

Effective date: 20061229

RBV Designated contracting states (corrected)

Designated state(s): DE IT

DAX Request for extension of the european patent (deleted)
RBV Designated contracting states (corrected)

Designated state(s): DE IT

17Q First examination report despatched

Effective date: 20071031

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE IT

REG Reference to a national code

Ref country code: DE

Ref legal event code: R096

Ref document number: 502005011501

Country of ref document: DE

Effective date: 20110728

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed

Effective date: 20120316

REG Reference to a national code

Ref country code: DE

Ref legal event code: R097

Ref document number: 502005011501

Country of ref document: DE

Effective date: 20120316

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20150421

Year of fee payment: 11

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: IT

Payment date: 20150428

Year of fee payment: 11

REG Reference to a national code

Ref country code: DE

Ref legal event code: R119

Ref document number: 502005011501

Country of ref document: DE

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20161101

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20160401